Simplifying and Factoring Algebraic Expressions

34 soru

Soru 1Soru →
For all real numbers xx such that x≠3x \neq 3 and x≠−5x \neq -5, the algebraic expression
(x2−9)2−4(x−3)2(x−3)(x+5)\frac{(x^2 - 9)^2 - 4(x - 3)^2}{(x - 3)(x + 5)}
can be simplified to the equivalent polynomial expression x2+ax+bx^2 + ax + b, where aa and bb are constants. What is the value of a+ba + b?
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Cevap: -5

Cevap

The value of a+ba + b is −5-5.
Factoring the numerator yields (x−3)2(x+1)(x+5)(x - 3)^2(x + 1)(x + 5). Canceling the common factors (x−3)(x - 3) and (x+5)(x + 5) with the denominator simplifies the expression to (x−3)(x+1)=x2−2x−3(x - 3)(x + 1) = x^2 - 2x - 3. Comparing this to x2+ax+bx^2 + ax + b identifies a=−2a = -2 and b=−3b = -3, giving a sum of a+b=−5a + b = -5.

Adım Adım Çözüm

1
Factor the numerator by recognizing (x2−9)=(x−3)(x+3)(x^2 - 9) = (x - 3)(x + 3)
(x2−9)2−4(x−3)2=[(x−3)(x+3)]2−4(x−3)2=(x−3)2(x+3)2−4(x−3)2(x^2 - 9)^2 - 4(x - 3)^2 = [(x - 3)(x + 3)]^2 - 4(x - 3)^2 = (x - 3)^2 (x + 3)^2 - 4(x - 3)^2
Applying the difference of squares identity inside the squared term allows factoring out common factors.
2
Factor out (x−3)2(x - 3)^2 from the numerator
(x−3)2[(x+3)2−4](x - 3)^2 \left[ (x + 3)^2 - 4 \right]
Extracting the greatest common algebraic factor simplifies the remaining expression.
3
Apply difference of squares to (x+3)2−4(x + 3)^2 - 4
(x+3)2−22=((x+3)−2)((x+3)+2)=(x+1)(x+5)(x + 3)^2 - 2^2 = ((x + 3) - 2)((x + 3) + 2) = (x + 1)(x + 5)
Recognizing (x+3)2−22(x + 3)^2 - 2^2 as A2−B2A^2 - B^2 yields factored linear terms directly.
4
Substitute the fully factored numerator back into the rational expression and simplify
\frac{(x - 3)^2 (x + 1)(x + 5)}{(x - 3)(x + 5)} = (x - 3)(x + 1)
Canceling non-zero common factors (x−3)(x - 3) and (x+5)(x + 5) simplifies the rational function.
5
Expand (x−3)(x+1)(x - 3)(x + 1) and determine a+ba + b
(x−3)(x+1)=x2−2x−3(x - 3)(x + 1) = x^2 - 2x - 3, so a=−2a = -2 and b=−3b = -3. Therefore, a+b=−2+(−3)=−5a + b = -2 + (-3) = -5.
Matching coefficients with x2+ax+bx^2 + ax + b gives a=−2a = -2 and b=−3b = -3.

Anahtar Kavram

Simplifying complex rational expressions through nested difference of squares factoring.
Soru 2Soru →

For all real numbers xx and yy such that 4x2+6xy+9y2≠04x^2 + 6xy + 9y^2 \neq 0 and 2x+3y≠02x + 3y \neq 0, which of the following expressions are equivalent to 8x3−27y34x2+6xy+9y2\frac{8x^3 - 27y^3}{4x^2 + 6xy + 9y^2}? Select all such expressions.

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Cevap: 2x−3y2x - 3y; −(3y−2x)-(3y - 2x); \frac{4x^2 - 9y^2}{2x + 3y}

Cevap

The equivalent expressions are 2x−3y2x - 3y, −(3y−2x)-(3y - 2x), and 4x2−9y22x+3y\frac{4x^2 - 9y^2}{2x + 3y}.
Factoring 8x3−27y38x^3 - 27y^3 as (2x−3y)(4x2+6xy+9y2)(2x - 3y)(4x^2 + 6xy + 9y^2) allows canceling the denominator, leaving 2x−3y2x - 3y. The expression 2x−3y2x - 3y is directly correct. Rearranging terms in −(3y−2x)-(3y - 2x) yields −3y+2x=2x−3y-3y + 2x = 2x - 3y, making it correct. Factoring 4x2−9y22x+3y\frac{4x^2 - 9y^2}{2x + 3y} as (2x−3y)(2x+3y)2x+3y\frac{(2x - 3y)(2x + 3y)}{2x + 3y} simplifies to 2x−3y2x - 3y, making it also correct.

Adım Adım Çözüm

1
Factor the numerator of the rational expression using the difference of cubes formula.
8x3−27y3=(2x)3−(3y)3=(2x−3y)((2x)2+(2x)(3y)+(3y)2)=(2x−3y)(4x2+6xy+9y2)8x^3 - 27y^3 = (2x)^3 - (3y)^3 = (2x - 3y)((2x)^2 + (2x)(3y) + (3y)^2) = (2x - 3y)(4x^2 + 6xy + 9y^2)
Recognizing 8x38x^3 as (2x)3(2x)^3 and 27y327y^3 as (3y)3(3y)^3 enables full polynomial factoring.
2
Simplify the fraction by canceling the common non-zero quadratic factor.
(2x−3y)(4x2+6xy+9y2)4x2+6xy+9y2=2x−3y\frac{(2x - 3y)(4x^2 + 6xy + 9y^2)}{4x^2 + 6xy + 9y^2} = 2x - 3y
Since 4x2+6xy+9y2≠04x^2 + 6xy + 9y^2 \neq 0, dividing common factors reduces the expression to linear form.
3
Evaluate each provided choice for algebraic equivalence to 2x−3y2x - 3y.
The expressions 2x−3y2x - 3y, −(3y−2x)=2x−3y-(3y - 2x) = 2x - 3y, and 4x2−9y22x+3y=(2x−3y)(2x+3y)2x+3y=2x−3y\frac{4x^2 - 9y^2}{2x + 3y} = \frac{(2x-3y)(2x+3y)}{2x+3y} = 2x - 3y are all algebraically identical.
Re-expressing or factoring alternative choices proves their equivalence to the simplified expression.

Anahtar Kavram

Factoring difference of cubes a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2) and difference of squares a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b)
Soru 3Soru →

For all real numbers aa and bb such that b≠0b \neq 0 and a≠−ba \neq -b, which of the following expressions is equivalent to a3b−ab3a2b+2ab2+b3\frac{a^3b - ab^3}{a^2b + 2ab^2 + b^3}?

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Cevap: a(a−b)a+b\frac{a(a - b)}{a + b}

Cevap

a(a−b)a+b\frac{a(a - b)}{a + b}
Factoring the numerator yields ab(a2−b2)=ab(a−b)(a+b)ab(a^2 - b^2) = ab(a - b)(a + b), and factoring the denominator yields b(a2+2ab+b2)=b(a+b)2b(a^2 + 2ab + b^2) = b(a + b)^2. Dividing both the numerator and the denominator by the common factor b(a+b)b(a + b) produces a(a−b)a+b\frac{a(a - b)}{a + b}.

Adım Adım Çözüm

1
Factor out the greatest common monomial factor from the numerator and denominator.
The numerator a3b−ab3a^3b - ab^3 becomes ab(a2−b2)ab(a^2 - b^2), and the denominator a2b+2ab2+b3a^2b + 2ab^2 + b^3 becomes b(a2+2ab+b2)b(a^2 + 2ab + b^2).
Extracting common terms simplifies polynomials prior to applying polynomial identities.
2
Apply polynomial algebraic identities to factor the remaining terms.
a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b) and a2+2ab+b2=(a+b)2a^2 + 2ab + b^2 = (a + b)^2. Thus, the expression becomes ab(a−b)(a+b)b(a+b)2\frac{ab(a - b)(a + b)}{b(a + b)^2}.
The difference of squares and perfect square trinomial identities allow complete factorization.
3
Cancel non-zero common factors from the numerator and denominator.
Canceling bb and one factor of (a+b)(a + b) leaves a(a−b)a+b\frac{a(a - b)}{a + b}.
Dividing both numerator and denominator by b(a+b)b(a + b) yields the simplified expression.

Anahtar Kavram

Simplifying rational expressions using common monomial factoring, difference of squares, and perfect square trinomial identities.
Tahmini Süre:1m 30s
Soru 4Soru →

For all real numbers xx and yy such that x≠yx \neq y, x≠−yx \neq -y, and x2+y2≠0x^2 + y^2 \neq 0, consider the algebraic expression:

E(x,y)=x4−y4x3−x2y+xy2−y3E(x, y) = \frac{x^4 - y^4}{x^3 - x^2y + xy^2 - y^3}

Which of the following expressions are equivalent to E(x,y)E(x, y) for all valid values of xx and yy? Select all such expressions.

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Cevap: x2−y2x−y\frac{x^2 - y^2}{x - y}; x3+y3x2−xy+y2\frac{x^3 + y^3}{x^2 - xy + y^2}

Cevap

The expressions equivalent to E(x,y)E(x, y) are x2−y2x−y\frac{x^2 - y^2}{x - y} and x3+y3x2−xy+y2\frac{x^3 + y^3}{x^2 - xy + y^2}.
Simplifying E(x,y)E(x, y) by factoring both numerator and denominator yields x+yx + y. The option with x2−y2x−y\frac{x^2 - y^2}{x - y} simplifies directly to x+yx + y by canceling (x−y)(x - y). The option with x3+y3x2−xy+y2\frac{x^3 + y^3}{x^2 - xy + y^2} uses the sum of cubes identity to factor the numerator into (x+y)(x2−xy+y2)(x + y)(x^2 - xy + y^2), which also cancels down to x+yx + y. Both of these options are mathematically identical to E(x,y)E(x, y).

Adım Adım Çözüm

1
Factor the numerator of E(x,y)E(x, y) using the difference of squares identity twice.
x4−y4=(x2−y2)(x2+y2)=(x−y)(x+y)(x2+y2)x^4 - y^4 = (x^2 - y^2)(x^2 + y^2) = (x - y)(x + y)(x^2 + y^2)
Decomposing higher-power binomials into linear and quadratic factors enables algebraic simplification.
2
Factor the denominator of E(x,y)E(x, y) by grouping terms.
x3−x2y+xy2−y3=x2(x−y)+y2(x−y)=(x−y)(x2+y2)x^3 - x^2y + xy^2 - y^3 = x^2(x - y) + y^2(x - y) = (x - y)(x^2 + y^2)
Grouping adjacent terms with shared factors allows factoring out (x−y)(x - y).
3
Simplify the full expression E(x,y)E(x, y) by canceling common non-zero factors.
E(x,y)=(x−y)(x+y)(x2+y2)(x−y)(x2+y2)=x+yE(x, y) = \frac{(x - y)(x + y)(x^2 + y^2)}{(x - y)(x^2 + y^2)} = x + y
Since x≠yx \neq y and x2+y2≠0x^2 + y^2 \neq 0, the factors (x−y)(x - y) and (x2+y2)(x^2 + y^2) cancel completely.
4
Evaluate the given options to determine which simplify to x+yx + y.
x2−y2x−y=x+y\frac{x^2 - y^2}{x - y} = x + y and x3+y3x2−xy+y2=x+y\frac{x^3 + y^3}{x^2 - xy + y^2} = x + y, whereas x3−y3x2+xy+y2=x−y\frac{x^3 - y^3}{x^2 + xy + y^2} = x - y and x2−y2x+y=x−y\frac{x^2 - y^2}{x + y} = x - y.
Matching each option's fully simplified form to x+yx + y identifies all valid equivalent expressions.

Anahtar Kavram

Simplifying rational expressions by polynomial factoring (grouping, difference of squares, and sum of cubes).
Soru 5Soru →

For all real numbers xx such that x≠−3x \neq -3, which of the following expressions is equivalent to 2x2−184x+12\frac{2x^2 - 18}{4x + 12}?

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Cevap: x−32\frac{x - 3}{2}

Cevap

The expression x−32\frac{x - 3}{2} is equivalent to the given rational expression.
Factoring the numerator gives 2(x2−9)=2(x−3)(x+3)2(x^2 - 9) = 2(x - 3)(x + 3) and factoring the denominator gives 4(x+3)4(x + 3). Canceling the non-zero common terms 2(x+3)2(x + 3) leaves x−32\frac{x - 3}{2}.

Adım Adım Çözüm

1
Factor out the greatest common factor from the numerator and denominator.
Numerator: 2x2−18=2(x2−9)2x^2 - 18 = 2(x^2 - 9); Denominator: 4x+12=4(x+3)4x + 12 = 4(x + 3).
Factoring out common numerical coefficients simplifies the expression and reveals algebraic patterns.
2
Apply the difference of squares formula to factor x2−9x^2 - 9.
x2−9=(x−3)(x+3)x^2 - 9 = (x - 3)(x + 3), so the numerator becomes 2(x−3)(x+3)2(x - 3)(x + 3).
The algebraic identity a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b) allows complete factoring of the numerator.
3
Cancel common factors shared by the numerator and denominator.
\frac{2(x - 3)(x + 3)}{4(x + 3)} = \frac{2(x - 3)}{4} = \frac{x - 3}{2}.
Since x≠−3x \neq -3, the factor (x+3)(x + 3) is non-zero and can be safely canceled along with reducing the constant ratio 24\frac{2}{4} to 12\frac{1}{2}.

Anahtar Kavram

Simplifying rational algebraic expressions by factoring common numerical factors and applying the difference of squares identity.
Soru 6Soru →

For all non-zero real numbers xx and yy, which of the following expressions is equivalent to 12x4y2−8x2y34x2y\frac{12x^4y^2 - 8x^2y^3}{4x^2y}?

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Cevap: 3x2y−2y23x^2y - 2y^2

Cevap

3x2y−2y23x^2y - 2y^2
Dividing each term in the numerator by 4x2y4x^2y yields 12x4y24x2y−8x2y34x2y=3x2y−2y2\frac{12x^4y^2}{4x^2y} - \frac{8x^2y^3}{4x^2y} = 3x^2y - 2y^2, which matches the correct expression.

Adım Adım Çözüm

1
Split the rational algebraic expression into two separate fractions by distributing the denominator.
12x4y24x2y−8x2y34x2y\frac{12x^4y^2}{4x^2y} - \frac{8x^2y^3}{4x^2y}
When dividing a polynomial by a monomial, each term of the numerator must be divided independently by the denominator.
2
Simplify the first term 12x4y24x2y\frac{12x^4y^2}{4x^2y}.
124⋅x4−2⋅y2−1=3x2y\frac{12}{4} \cdot x^{4-2} \cdot y^{2-1} = 3x^2y
Divide the numerical coefficients and apply the exponent quotient rule am/an=am−na^m / a^n = a^{m-n} for each variable.
3
Simplify the second term 8x2y34x2y\frac{8x^2y^3}{4x^2y}.
84⋅x2−2⋅y3−1=2(1)y2=2y2\frac{8}{4} \cdot x^{2-2} \cdot y^{3-1} = 2(1)y^2 = 2y^2
Divide the coefficients and apply the exponent quotient rule, noting that x0=1x^0 = 1 for non-zero xx.
4
Combine the simplified terms with the original subtraction operator.
3x2y−2y23x^2y - 2y^2
Combine terms to form the final simplified expression.

Anahtar Kavram

Simplifying algebraic fractions by distributing a monomial denominator across numerator terms and applying exponent rules.
Tahmini Süre:45s
Soru 7Soru →
For all non-zero real numbers aa and bb such that a≠ba \neq b and a≠−ba \neq -b, which of the following expressions is equivalent to
a−2−b−2a−1−b−1÷a2+ab+b2a3−b3?\frac{a^{-2} - b^{-2}}{a^{-1} - b^{-1}} \div \frac{a^2 + ab + b^2}{a^3 - b^3}?
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Cevap: a2−b2ab\frac{a^2 - b^2}{ab}

Cevap

a2−b2ab\frac{a^2 - b^2}{ab}
Simplifying a−2−b−2a−1−b−1\frac{a^{-2} - b^{-2}}{a^{-1} - b^{-1}} yields a+bab\frac{a + b}{ab} after canceling (b−a)(b - a) from both numerator and denominator. Simplifying a2+ab+b2a3−b3\frac{a^2 + ab + b^2}{a^3 - b^3} yields 1a−b\frac{1}{a - b} using the difference of cubes identity. Dividing a+bab\frac{a + b}{ab} by 1a−b\frac{1}{a - b} gives a+bab⋅(a−b)=a2−b2ab\frac{a + b}{ab} \cdot (a - b) = \frac{a^2 - b^2}{ab}.

Adım Adım Çözüm

1
Simplify the first rational expression a−2−b−2a−1−b−1\frac{a^{-2} - b^{-2}}{a^{-1} - b^{-1}}
1a2−1b21a−1b=b2−a2a2b2b−aab=(b−a)(b+a)a2b2⋅abb−a=a+bab\frac{\frac{1}{a^2} - \frac{1}{b^2}}{\frac{1}{a} - \frac{1}{b}} = \frac{\frac{b^2 - a^2}{a^2 b^2}}{\frac{b - a}{ab}} = \frac{(b - a)(b + a)}{a^2 b^2} \cdot \frac{ab}{b - a} = \frac{a + b}{ab}
Convert negative exponents to fractions, find common denominators, and cancel the common non-zero factor (b−a)(b - a).
2
Simplify the second rational expression a2+ab+b2a3−b3\frac{a^2 + ab + b^2}{a^3 - b^3}
a2+ab+b2(a−b)(a2+ab+b2)=1a−b\frac{a^2 + ab + b^2}{(a - b)(a^2 + ab + b^2)} = \frac{1}{a - b}
Factor the denominator using the difference of cubes identity a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2).
3
Divide the simplified first expression by the simplified second expression
a+bab÷1a−b=a+bab⋅(a−b)=(a+b)(a−b)ab=a2−b2ab\frac{a + b}{ab} \div \frac{1}{a - b} = \frac{a + b}{ab} \cdot (a - b) = \frac{(a + b)(a - b)}{ab} = \frac{a^2 - b^2}{ab}
Multiply by the reciprocal of the second expression and apply the difference of squares identity.

Anahtar Kavram

Simplifying complex fractions and factoring using difference of squares and difference of cubes identities.
Soru 8Soru →

For all real numbers aa and bb, which of the following expressions are equivalent to (a+b)2−(a−b)2(a + b)^2 - (a - b)^2? Select all that apply.

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Cevap: 4ab4ab; (2a)(2b)(2a)(2b)

Cevap

The expressions 4ab4ab and (2a)(2b)(2a)(2b) are equivalent to (a+b)2−(a−b)2(a + b)^2 - (a - b)^2.
Expanding the squared expressions gives (a+b)2=a2+2ab+b2(a+b)^2 = a^2 + 2ab + b^2 and (a−b)2=a2−2ab+b2(a-b)^2 = a^2 - 2ab + b^2. Subtracting the second expression from the first yields (a2+2ab+b2)−(a2−2ab+b2)=4ab(a^2 + 2ab + b^2) - (a^2 - 2ab + b^2) = 4ab. Since (2a)(2b)(2a)(2b) also equals 4ab4ab, both 4ab4ab and (2a)(2b)(2a)(2b) are mathematically equivalent to the original expression.

Adım Adım Çözüm

1
Expand (a+b)2(a + b)^2 using the binomial square formula.
(a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2
Squaring a sum produces a trinomial containing two squared terms and a middle product term.
2
Expand (a−b)2(a - b)^2 using the binomial square formula.
(a−b)2=a2−2ab+b2(a - b)^2 = a^2 - 2ab + b^2
Squaring a difference produces a trinomial with a negative middle product term.
3
Subtract the second expanded trinomial from the first.
(a2+2ab+b2)−(a2−2ab+b2)=a2−a2+2ab+2ab+b2−b2=4ab(a^2 + 2ab + b^2) - (a^2 - 2ab + b^2) = a^2 - a^2 + 2ab + 2ab + b^2 - b^2 = 4ab
Distributing the negative sign across (a2−2ab+b2)(a^2 - 2ab + b^2) changes the signs inside the second set of parentheses.
4
Compare the simplified result 4ab4ab against all given choices.
Both 4ab4ab and (2a)(2b)=4ab(2a)(2b) = 4ab are identical to the calculated result.
Algebraic multiplication shows (2a)(2b)=4ab(2a)(2b) = 4ab.

Anahtar Kavram

Binomial expansion and combination of like terms
Soru 9Soru →

When the expression 3x2−12x−2\frac{3x^2 - 12}{x - 2} is completely simplified, it can be written in the form ax+bax + b for all x≠2x \neq 2, where aa and bb are constants. What is the value of a+ba + b?

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Cevap: 9

Cevap

The value of a+ba + b is 9.
Factoring the numerator gives 3x2−12=3(x2−4)=3(x−2)(x+2)3x^2 - 12 = 3(x^2 - 4) = 3(x - 2)(x + 2). Canceling the common factor (x−2)(x - 2) in the denominator yields 3(x+2)3(x + 2), which expands to 3x+63x + 6. Matching this expression to ax+bax + b reveals a=3a = 3 and b=6b = 6. Adding these constants gives a+b=9a + b = 9.

Adım Adım Çözüm

1
Factor the numerator of the rational expression.
3x2−12=3(x2−4)=3(x−2)(x+2)3x^2 - 12 = 3(x^2 - 4) = 3(x - 2)(x + 2)
Factoring out the common numerical factor 3 and using the difference of squares identity (u2−v2=(u−v)(u+v))(u^2 - v^2 = (u-v)(u+v)) completely factors the numerator.
2
Simplify the expression by canceling common factors.
3(x−2)(x+2)x−2=3(x+2)=3x+6\frac{3(x - 2)(x + 2)}{x - 2} = 3(x + 2) = 3x + 6
Because x≠2x \neq 2, the factor (x−2)(x - 2) is non-zero and can be canceled from both numerator and denominator.
3
Identify the values of aa and bb and compute a+ba + b.
a=3a = 3, b=6b = 6, so a+b=3+6=9a + b = 3 + 6 = 9
Comparing 3x+63x + 6 to ax+bax + b gives a=3a = 3 and b=6b = 6.

Anahtar Kavram

Factoring algebraic expressions using common monomial factors and the difference of squares to simplify rational expressions.
Soru 10Soru →

For all real numbers xx such that x≠5x \neq 5, which of the following expressions is equivalent to x2−253x−15\frac{x^2 - 25}{3x - 15}?

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Cevap: x+53\frac{x + 5}{3}

Cevap

The expression x+53\frac{x + 5}{3} is equivalent to the given rational expression for all x≠5x \neq 5.
Factoring the numerator as a difference of squares gives (x−5)(x+5)(x - 5)(x + 5), and factoring the denominator gives 3(x−5)3(x - 5). Dividing out the common factor (x−5)(x - 5) simplifies the expression to x+53\frac{x + 5}{3}.

Adım Adım Çözüm

1
Factor the numerator using the difference of squares identity.
x2−25=(x−5)(x+5)x^2 - 25 = (x - 5)(x + 5)
The difference of squares a2−b2a^2 - b^2 factors into (a−b)(a+b)(a - b)(a + b).
2
Factor out the greatest common factor from the denominator.
3x−15=3(x−5)3x - 15 = 3(x - 5)
Both terms in 3x−153x - 15 share a common factor of 33.
3
Divide out the common binomial factor (x−5)(x - 5) from the numerator and denominator.
(x−5)(x+5)3(x−5)=x+53\frac{(x - 5)(x + 5)}{3(x - 5)} = \frac{x + 5}{3}
Since x≠5x \neq 5, the factor (x−5)(x - 5) is non-zero and can be cancelled.

Anahtar Kavram

Simplifying rational algebraic expressions by factoring difference of squares and common linear factors.
Soru 11Soru →
For all real numbers xx such that x≠3x \neq 3 and x≠−3x \neq -3, the algebraic expression
x4−81x2−9⋅x3−27x2+3x+9−x(x−3)2x2−9\frac{\frac{x^4 - 81}{x^2 - 9} \cdot \frac{x^3 - 27}{x^2 + 3x + 9} - x(x - 3)^2}{x^2 - 9}
simplifies to a constant value. What is the value of this constant?
Cevabı ve açıklamayı göster

Cevap: 3

Cevap

The simplified expression evaluates to the constant value 33.
Factoring the numerator components using difference of squares and difference of cubes simplifies the product term to x3−3x2+9x−27x^3 - 3x^2 + 9x - 27. Subtracting x(x−3)2=x3−6x2+9xx(x - 3)^2 = x^3 - 6x^2 + 9x simplifies the entire numerator to 3x2−27=3(x2−9)3x^2 - 27 = 3(x^2 - 9). Dividing by the denominator (x2−9)(x^2 - 9) cancels out the variable terms entirely, yielding the constant value 3.

Adım Adım Çözüm

1
Simplify the first rational component using the difference of squares identity
x4−81x2−9=(x2−9)(x2+9)x2−9=x2+9\frac{x^4 - 81}{x^2 - 9} = \frac{(x^2 - 9)(x^2 + 9)}{x^2 - 9} = x^2 + 9
Since x≠±3x \neq \pm 3, x2−9≠0x^2 - 9 \neq 0, allowing direct cancellation of (x2−9)(x^2 - 9).
2
Simplify the second rational component using the difference of cubes identity
x3−27x2+3x+9=(x−3)(x2+3x+9)x2+3x+9=x−3\frac{x^3 - 27}{x^2 + 3x + 9} = \frac{(x - 3)(x^2 + 3x + 9)}{x^2 + 3x + 9} = x - 3
Applying a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2) where a=xa = x and b=3b = 3 allows cancellation of the quadratic factor.
3
Multiply the simplified expressions
(x2+9)(x−3)=x3−3x2+9x−27(x^2 + 9)(x - 3) = x^3 - 3x^2 + 9x - 27
Distribute each term of the binomials to get the expanded polynomial.
4
Expand the subtracted term in the numerator
x(x−3)2=x(x2−6x+9)=x3−6x2+9xx(x - 3)^2 = x(x^2 - 6x + 9) = x^3 - 6x^2 + 9x
Expand (x−3)2=x2−6x+9(x - 3)^2 = x^2 - 6x + 9 and distribute xx.
5
Subtract the two expanded expressions to simplify the entire numerator
(x3−3x2+9x−27)−(x3−6x2+9x)=3x2−27=3(x2−9)(x^3 - 3x^2 + 9x - 27) - (x^3 - 6x^2 + 9x) = 3x^2 - 27 = 3(x^2 - 9)
Combine like terms; x3x^3 and 9x9x terms cancel out, leaving 3x2−273x^2 - 27.
6
Divide the simplified numerator by the main denominator
3(x2−9)x2−9=3\frac{3(x^2 - 9)}{x^2 - 9} = 3
Cancel the common factor (x2−9)(x^2 - 9) from numerator and denominator.

Anahtar Kavram

Simplifying complex algebraic expressions via polynomial factoring (difference of squares and difference of cubes) and combining like terms.
Soru 12Soru →

If aa and bb are distinct real numbers, what is the simplified form of the algebraic expression a3−b3−a(a2−b2)+b(a−b)2a−b\frac{a^3 - b^3 - a(a^2 - b^2) + b(a - b)^2}{a - b}?

Cevabı ve açıklamayı göster

Cevap: abab

Cevap

abab
Factoring the common binomial term (a−b)(a - b) from each term in the numerator yields (a−b)[(a2+ab+b2)−a(a+b)+b(a−b)](a - b)[(a^2 + ab + b^2) - a(a + b) + b(a - b)]. Expanding inside the brackets gives a2+ab+b2−a2−ab+ab−b2a^2 + ab + b^2 - a^2 - ab + ab - b^2, which reduces completely to abab. Dividing (a−b)(ab)(a - b)(ab) by (a−b)(a - b) leaves the simplified expression abab.

Adım Adım Çözüm

1
Apply standard algebraic factoring identities to each component of the numerator.
a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2), −a(a2−b2)=−a(a−b)(a+b)-a(a^2 - b^2) = -a(a - b)(a + b), and b(a−b)2=b(a−b)(a−b)b(a - b)^2 = b(a - b)(a - b).
Rewriting each grouping with the common binomial factor (a−b)(a - b) allows for structured factoring of the numerator.
2
Factor out (a−b)(a - b) from the entire numerator.
Numerator =(a−b)[(a2+ab+b2)−a(a+b)+b(a−b)]= (a - b) \left[ (a^2 + ab + b^2) - a(a + b) + b(a - b) \right].
Extracting the common factor isolates the remaining polynomial terms inside brackets.
3
Expand and collect like terms within the bracketed expression.
(a2+ab+b2)−(a2+ab)+(ab−b2)=a2−a2+ab−ab+ab+b2−b2=ab(a^2 + ab + b^2) - (a^2 + ab) + (ab - b^2) = a^2 - a^2 + ab - ab + ab + b^2 - b^2 = ab.
Canceling opposite terms (a2−a2=0a^2 - a^2 = 0, ab−ab=0ab - ab = 0, b2−b2=0b^2 - b^2 = 0) leaves only abab inside the brackets.
4
Divide the factored numerator by the denominator (a−b)(a - b).
(a−b)(ab)a−b=ab\frac{(a - b)(ab)}{a - b} = ab.
Since aa and bb are distinct (a≠ba \neq b), a−b≠0a - b \neq 0, allowing non-zero cancellation.

Anahtar Kavram

Simplifying complex algebraic expressions by factoring common binomial terms and applying algebraic identities
Soru 13Soru →

Given non-zero real numbers xx and yy where ∣x∣≠∣y∣|x| \neq |y|, simplify the complex rational expression:

x3+y3x2−y2−x2y−xy2(x−y)2x4−y4x3+x2y+xy2+y3\frac{\frac{x^3 + y^3}{x^2 - y^2} - \frac{x^2y - xy^2}{(x - y)^2}}{\frac{x^4 - y^4}{x^3 + x^2y + xy^2 + y^3}}

Which of the following represents the completely simplified expression?

Cevabı ve açıklamayı göster

Cevap: 1

Cevap

1
Both the entire complex numerator and the entire complex denominator independently simplify to x−yx - y. Consequently, dividing the numerator x−yx - y by the denominator x−yx - y gives 11.

Adım Adım Çözüm

1
Simplify the first term of the main numerator
\frac{x^3 + y^3}{x^2 - y^2} = \frac{(x + y)(x^2 - xy + y^2)}{(x - y)(x + y)} = \frac{x^2 - xy + y^2}{x - y}
Factor the sum of cubes in the numerator and the difference of squares in the denominator, then cancel the common factor (x+y)(x + y).
2
Simplify the second term of the main numerator
\frac{x^2y - xy^2}{(x - y)^2} = \frac{xy(x - y)}{(x - y)^2} = \frac{xy}{x - y}
Factor out the greatest common factor xyxy from the numerator and cancel one factor of (x−y)(x - y).
3
Subtract the simplified terms in the main numerator
\frac{x^2 - xy + y^2}{x - y} - \frac{xy}{x - y} = \frac{x^2 - 2xy + y^2}{x - y} = \frac{(x - y)^2}{x - y} = x - y
Combine the numerators over the common denominator (x−y)(x - y), factor the perfect square trinomial x2−2xy+y2=(x−y)2x^2 - 2xy + y^2 = (x - y)^2, and simplify.
4
Simplify the main denominator
\frac{x^4 - y^4}{x^3 + x^2y + xy^2 + y^3} = \frac{(x - y)(x + y)(x^2 + y^2)}{x^2(x + y) + y^2(x + y)} = \frac{(x - y)(x + y)(x^2 + y^2)}{(x + y)(x^2 + y^2)} = x - y
Factor the numerator using difference of squares twice, factor the denominator by grouping, and cancel common factors (x+y)(x2+y2)(x + y)(x^2 + y^2).
5
Divide the main numerator by the main denominator
\frac{x - y}{x - y} = 1
Divide the simplified main numerator (x−yx - y) by the simplified main denominator (x−yx - y).

Anahtar Kavram

Multi-step algebraic expression simplification using special factoring identities (sum/difference of cubes, difference of squares, quadratic trinomials, and factoring by grouping).
Tahmini Süre:2m 0s
Soru 14Soru →

For all real numbers xx and yy such that x2+xy+y2≠0x^2 + xy + y^2 \neq 0, which of the following expressions are equivalent to x6−y6x2+xy+y2\frac{x^6 - y^6}{x^2 + xy + y^2}? Select all such expressions.

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Cevabı ve açıklamayı göster

Cevap: (x2−y2)(x2−xy+y2)(x^2 - y^2)(x^2 - xy + y^2); (x−y)(x3+y3)(x - y)(x^3 + y^3); x4−x3y+xy3−y4x^4 - x^3 y + x y^3 - y^4

Cevap

The equivalent expressions are (x2−y2)(x2−xy+y2)(x^2 - y^2)(x^2 - xy + y^2), (x−y)(x3+y3)(x - y)(x^3 + y^3), and x4−x3y+xy3−y4x^4 - x^3y + xy^3 - y^4.
Factoring the numerator x6−y6x^6 - y^6 as a difference of squares yields (x3−y3)(x3+y3)(x^3 - y^3)(x^3 + y^3). Applying the difference of cubes identity x3−y3=(x−y)(x2+xy+y2)x^3 - y^3 = (x - y)(x^2 + xy + y^2) enables cancellation of the non-zero denominator x2+xy+y2x^2 + xy + y^2, leaving (x−y)(x3+y3)(x - y)(x^3 + y^3). Expanding this product gives x4−x3y+xy3−y4x^4 - x^3y + xy^3 - y^4. Furthermore, factoring x3+y3x^3 + y^3 as (x+y)(x2−xy+y2)(x + y)(x^2 - xy + y^2) and regrouping (x−y)(x+y)(x - y)(x + y) gives (x2−y2)(x2−xy+y2)(x^2 - y^2)(x^2 - xy + y^2). Consequently, the three valid equivalent forms are (x2−y2)(x2−xy+y2)(x^2 - y^2)(x^2 - xy + y^2), (x−y)(x3+y3)(x - y)(x^3 + y^3), and x4−x3y+xy3−y4x^4 - x^3y + xy^3 - y^4.

Adım Adım Çözüm

1
Factor the numerator x6−y6x^6 - y^6 as a difference of squares.
x6−y6=(x3)2−(y3)2=(x3−y3)(x3+y3)x^6 - y^6 = (x^3)^2 - (y^3)^2 = (x^3 - y^3)(x^3 + y^3)
Applying the difference of squares identity a2−b2=(a−b)(a+b)a^2 - b^2 = (a - b)(a + b) with a=x3a = x^3 and b=y3b = y^3.
2
Apply the difference of cubes identity to x3−y3x^3 - y^3.
x3−y3=(x−y)(x2+xy+y2)x^3 - y^3 = (x - y)(x^2 + xy + y^2)
This reveals the non-zero quadratic factor present in the denominator.
3
Substitute into the original fraction and cancel the common factor (x2+xy+y2)(x^2 + xy + y^2).
(x−y)(x2+xy+y2)(x3+y3)x2+xy+y2=(x−y)(x3+y3)\frac{(x - y)(x^2 + xy + y^2)(x^3 + y^3)}{x^2 + xy + y^2} = (x - y)(x^3 + y^3)
Since x2+xy+y2≠0x^2 + xy + y^2 \neq 0, dividing numerator and denominator by (x2+xy+y2)(x^2 + xy + y^2) simplifies the expression to (x−y)(x3+y3)(x - y)(x^3 + y^3).
4
Expand (x−y)(x3+y3)(x - y)(x^3 + y^3) to check for equivalent expanded polynomial forms.
(x−y)(x3+y3)=x4+xy3−x3y−y4=x4−x3y+xy3−y4(x - y)(x^3 + y^3) = x^4 + xy^3 - x^3y - y^4 = x^4 - x^3y + xy^3 - y^4
Distributing terms verifies polynomial equivalence.
5
Factor x3+y3x^3 + y^3 and regroup to find another equivalent factored representation.
(x−y)(x3+y3)=(x−y)(x+y)(x2−xy+y2)=(x2−y2)(x2−xy+y2)(x - y)(x^3 + y^3) = (x - y)(x + y)(x^2 - xy + y^2) = (x^2 - y^2)(x^2 - xy + y^2)
Applying the sum of cubes identity x3+y3=(x+y)(x2−xy+y2)x^3 + y^3 = (x + y)(x^2 - xy + y^2) and combining (x−y)(x+y)=x2−y2(x - y)(x + y) = x^2 - y^2.

Anahtar Kavram

Factoring higher-degree algebraic expressions using difference of squares and sum/difference of cubes identities
Soru 15Soru →

For all real numbers xx and yy such that x≠yx \neq y and x≠−yx \neq -y, which of the following is equivalent to the algebraic expression x3(x+2y)−y3(y+2x)x2−y2\frac{x^3(x + 2y) - y^3(y + 2x)}{x^2 - y^2}?

Cevabı ve açıklamayı göster

Cevap: (x+y)2(x + y)^2

Cevap

The simplified expression is (x+y)2(x + y)^2.
Expanding and grouping the terms in the numerator gives (x4−y4)+2xy(x2−y2)=(x2−y2)(x2+2xy+y2)=(x2−y2)(x+y)2(x^4 - y^4) + 2xy(x^2 - y^2) = (x^2 - y^2)(x^2 + 2xy + y^2) = (x^2 - y^2)(x + y)^2. Canceling the common factor (x2−y2)(x^2 - y^2) from both the numerator and the denominator leaves (x+y)2(x + y)^2.

Adım Adım Çözüm

1
Expand the numerator terms
x3(x+2y)−y3(y+2x)=x4+2x3y−y4−2xy3x^3(x + 2y) - y^3(y + 2x) = x^4 + 2x^3y - y^4 - 2xy^3
Apply the distributive property to remove parentheses in the numerator.
2
Group the terms in the numerator to factor
(x4−y4)+(2x3y−2xy3)=(x2−y2)(x2+y2)+2xy(x2−y2)(x^4 - y^4) + (2x^3y - 2xy^3) = (x^2 - y^2)(x^2 + y^2) + 2xy(x^2 - y^2)
Use difference of squares on x4−y4x^4 - y^4 and factor out the greatest common factor 2xy2xy from the remaining terms.
3
Factor out the common term (x2−y2)(x^2 - y^2) from the numerator
(x2−y2)(x2+y2+2xy)=(x2−y2)(x+y)2(x^2 - y^2)(x^2 + y^2 + 2xy) = (x^2 - y^2)(x + y)^2
Recognize that x2+2xy+y2x^2 + 2xy + y^2 is the perfect square binomial (x+y)2(x + y)^2.
4
Simplify the rational expression by canceling common factors
\frac{(x^2 - y^2)(x + y)^2}{x^2 - y^2} = (x + y)^2
Divide numerator and denominator by (x2−y2)(x^2 - y^2), which is non-zero since x≠±yx \neq \pm y.

Anahtar Kavram

Factoring high-degree algebraic expressions by grouping terms, recognizing difference of squares, and applying perfect square binomial identities.
Tahmini Süre:2m 0s
Soru 16Soru →
If aa, bb, and cc are pairwise distinct real numbers, which of the following expressions is equivalent to
a3(b−c)+b3(c−a)+c3(a−b)(a−b)(b−c)(c−a)?\frac{a^3(b - c) + b^3(c - a) + c^3(a - b)}{(a - b)(b - c)(c - a)}?
Cevabı ve açıklamayı göster

Cevap: −(a+b+c)-(a + b + c)

Cevap

−(a+b+c)-(a + b + c)
Factoring the numerator by using the Factor Theorem and cyclic symmetry reveals that a3(b−c)+b3(c−a)+c3(a−b)=−(a−b)(b−c)(c−a)(a+b+c)a^3(b - c) + b^3(c - a) + c^3(a - b) = -(a - b)(b - c)(c - a)(a + b + c). Dividing this by the denominator (a−b)(b−c)(c−a)(a - b)(b - c)(c - a) cancels the pairwise difference terms, leaving −(a+b+c)-(a + b + c).

Adım Adım Çözüm

1
Analyze the numerator for polynomial factors using cyclic symmetry
Let P(a,b,c)=a3(b−c)+b3(c−a)+c3(a−b)P(a, b, c) = a^3(b - c) + b^3(c - a) + c^3(a - b). If a=ba = b, then P(b,b,c)=b3(b−c)+b3(c−b)+0=0P(b, b, c) = b^3(b - c) + b^3(c - b) + 0 = 0. By the Factor Theorem, (a−b)(a - b) is a factor. By cyclic symmetry, (b−c)(b - c) and (c−a)(c - a) are also factors.
Identifying linear factors reduces the polynomial simplification problem.
2
Determine the degree and form of the remaining factor
P(a,b,c)P(a, b, c) is a homogeneous polynomial of degree 4, while (a−b)(b−c)(c−a)(a - b)(b - c)(c - a) has degree 3. Therefore, the remaining factor must be a homogeneous symmetric polynomial of degree 1, which takes the form k(a+b+c)k(a + b + c) for some constant kk.
Homogeneous degree properties dictate the algebraic structure of the quotient.
3
Find the constant kk by substituting test values
Let a=0a = 0, b=1b = 1, and c=2c = 2. Evaluating P(0,1,2)=0+13(2−0)+23(0−1)=2−8=−6P(0, 1, 2) = 0 + 1^3(2 - 0) + 2^3(0 - 1) = 2 - 8 = -6. The factor product gives (0−1)(1−2)(2−0)=(−1)(−1)(2)=2(0 - 1)(1 - 2)(2 - 0) = (-1)(-1)(2) = 2. Setting 2⋅k(0+1+2)=−6  ⟹  6k=−6  ⟹  k=−12 \cdot k(0 + 1 + 2) = -6 \implies 6k = -6 \implies k = -1.
Evaluating at convenient integer values determines the missing constant scalar.
4
Divide the factored numerator by the denominator
−(a−b)(b−c)(c−a)(a+b+c)(a−b)(b−c)(c−a)=−(a+b+c)\frac{-(a - b)(b - c)(c - a)(a + b + c)}{(a - b)(b - c)(c - a)} = -(a + b + c).
Canceling common non-zero factors yields the simplified expression.

Anahtar Kavram

Factoring Cyclic Symmetric Polynomials
Soru 17Soru →

For all real numbers xx and yy such that ∣x∣≠∣y∣|x| \neq |y| and x2+y2≠0x^2 + y^2 \neq 0, consider the algebraic expression:

P(x,y)=(x3+y3−x2y−xy2x4−y4)⋅(x3+y3x2−xy+y2)P(x, y) = \left(\frac{x^3 + y^3 - x^2 y - xy^2}{x^4 - y^4}\right) \cdot \left(\frac{x^3 + y^3}{x^2 - xy + y^2}\right)

Which of the following expressions are equivalent to P(x,y)P(x, y) for all valid values of xx and yy? Indicate all such expressions.

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: x4−y4(x2+y2)2\frac{x^4 - y^4}{(x^2 + y^2)^2}; 1−2y2x2+y21 - \frac{2y^2}{x^2 + y^2}

Cevap

The expressions equivalent to P(x,y)P(x, y) are x4−y4(x2+y2)2\frac{x^4 - y^4}{(x^2 + y^2)^2} and 1−2y2x2+y21 - \frac{2y^2}{x^2 + y^2}.
The given expression simplifies to x2−y2x2+y2\frac{x^2 - y^2}{x^2 + y^2}. The option x4−y4(x2+y2)2\frac{x^4 - y^4}{(x^2 + y^2)^2} simplifies directly to x2−y2x2+y2\frac{x^2 - y^2}{x^2 + y^2} after factoring the numerator. The option 1−2y2x2+y21 - \frac{2y^2}{x^2 + y^2} simplifies to x2+y2−2y2x2+y2=x2−y2x2+y2\frac{x^2 + y^2 - 2y^2}{x^2 + y^2} = \frac{x^2 - y^2}{x^2 + y^2} when combined over a common denominator.

Adım Adım Çözüm

1
Factor the numerator of the first rational term by grouping terms.
x3+y3−x2y−xy2=x2(x−y)−y2(x−y)=(x2−y2)(x−y)=(x−y)2(x+y)x^3 + y^3 - x^2 y - xy^2 = x^2(x - y) - y^2(x - y) = (x^2 - y^2)(x - y) = (x - y)^2 (x + y)
Grouping allows rewriting four polynomial terms into product of linear/quadratic factors.
2
Factor the denominator of the first rational term as a difference of squares.
x4−y4=(x2−y2)(x2+y2)=(x−y)(x+y)(x2+y2)x^4 - y^4 = (x^2 - y^2)(x^2 + y^2) = (x - y)(x + y)(x^2 + y^2)
Decomposing x4−y4x^4 - y^4 into simpler factors reveals common factors with the numerator.
3
Simplify the first rational term by canceling common factors (x−y)(x+y)(x - y)(x + y).
\frac{(x - y)^2(x + y)}{(x - y)(x + y)(x^2 + y^2)} = \frac{x - y}{x^2 + y^2}
Canceling non-zero common factors simplifies the fraction.
4
Factor the numerator of the second rational term using the sum of cubes formula.
x3+y3=(x+y)(x2−xy+y2)x^3 + y^3 = (x + y)(x^2 - xy + y^2)
Applying the sum of cubes identity exposes the irreducible quadratic factor present in the denominator.
5
Simplify the second rational term and multiply the result by the simplified first term.
P(x,y)=(x−yx2+y2)⋅(x+y)=(x−y)(x+y)x2+y2=x2−y2x2+y2P(x, y) = \left(\frac{x - y}{x^2 + y^2}\right) \cdot (x + y) = \frac{(x - y)(x + y)}{x^2 + y^2} = \frac{x^2 - y^2}{x^2 + y^2}
Multiplying the simplified forms yields the simplest explicit representation of P(x,y)P(x, y).
6
Verify equivalence of the options against x2−y2x2+y2\frac{x^2 - y^2}{x^2 + y^2}.
The option x4−y4(x2+y2)2=(x2−y2)(x2+y2)(x2+y2)2=x2−y2x2+y2\frac{x^4 - y^4}{(x^2 + y^2)^2} = \frac{(x^2 - y^2)(x^2 + y^2)}{(x^2 + y^2)^2} = \frac{x^2 - y^2}{x^2 + y^2}, and the option 1−2y2x2+y2=x2+y2−2y2x2+y2=x2−y2x2+y21 - \frac{2y^2}{x^2 + y^2} = \frac{x^2 + y^2 - 2y^2}{x^2 + y^2} = \frac{x^2 - y^2}{x^2 + y^2}. Both match P(x,y)P(x, y).
Transforming algebraic expressions under common denominators or factoring confirms equivalence.

Anahtar Kavram

Simplifying complex algebraic expressions using factoring by grouping, difference of squares, sum of cubes, and common denominator manipulation.
Soru 18Soru →
For all real numbers xx and yy such that ∣x∣≠∣y∣|x| \neq |y|, which of the following expressions is equivalent to x3+x2y+x2−y3−xy2−y2x2−y2?\frac{x^3 + x^2y + x^2 - y^3 - xy^2 - y^2}{x^2 - y^2}?
Cevabı ve açıklamayı göster

Cevap: x+y+1x + y + 1

Cevap

x+y+1x + y + 1
Factoring the numerator by grouping yields (x−y)(x+y)(x+y+1)(x - y)(x + y)(x + y + 1). Factoring the denominator gives (x−y)(x+y)(x - y)(x + y). Canceling the non-zero common factor (x−y)(x+y)(x - y)(x + y) leaves the simplified expression x+y+1x + y + 1.

Adım Adım Çözüm

1
Group terms in the numerator to identify common factor pairs.
N=(x3−y3)+(x2y−xy2)+(x2−y2)N = (x^3 - y^3) + (x^2y - xy^2) + (x^2 - y^2)
Grouping cubic terms, quadratic cross-terms, and difference of squares separately allows factoring out fundamental algebraic patterns.
2
Apply standard algebraic formulas to each grouped term.
N=(x−y)(x2+xy+y2)+xy(x−y)+(x−y)(x+y)N = (x - y)(x^2 + xy + y^2) + xy(x - y) + (x - y)(x + y)
Using difference of cubes x3−y3=(x−y)(x2+xy+y2)x^3 - y^3 = (x-y)(x^2+xy+y^2) and difference of squares x2−y2=(x−y)(x+y)x^2 - y^2 = (x-y)(x+y) reveals a common (x−y)(x-y) factor across all terms.
3
Factor out (x−y)(x - y) from the numerator and simplify the remaining polynomial.
N=(x−y)[(x2+xy+y2)+xy+(x+y)]=(x−y)[x2+2xy+y2+x+y]N = (x - y)\left[(x^2 + xy + y^2) + xy + (x + y)\right] = (x - y)\left[x^2 + 2xy + y^2 + x + y\right]
Combining like terms inside the bracket simplifies the expression.
4
Recognize the perfect square trinomial inside the expression.
N=(x−y)[(x+y)2+(x+y)]=(x−y)(x+y)(x+y+1)N = (x - y)\left[(x + y)^2 + (x + y)\right] = (x - y)(x + y)(x + y + 1)
Rewriting x2+2xy+y2x^2 + 2xy + y^2 as (x+y)2(x + y)^2 allows factoring out (x+y)(x + y).
5
Divide the factored numerator by the denominator.
(x−y)(x+y)(x+y+1)(x−y)(x+y)=x+y+1\frac{(x - y)(x + y)(x + y + 1)}{(x - y)(x + y)} = x + y + 1
Since ∣x∣≠∣y∣|x| \neq |y|, both (x−y)(x - y) and (x+y)(x + y) are non-zero and can be canceled.

Anahtar Kavram

Factoring multivariable polynomials using grouping, difference of cubes, and difference of squares formulas.
Soru 19Soru →

For pairwise distinct real numbers xx, yy, and zz, consider the algebraic expression:

E(x,y,z)=(x2−y2)3+(y2−z2)3+(z2−x2)3(x−y)3+(y−z)3+(z−x)3E(x, y, z) = \frac{(x^2 - y^2)^3 + (y^2 - z^2)^3 + (z^2 - x^2)^3}{(x - y)^3 + (y - z)^3 + (z - x)^3}

If x=5x = 5, y=3y = 3, and z=1z = 1, what is the numerical value of E(5,3,1)E(5, 3, 1)?

Cevabı ve açıklamayı göster

Cevap: 192

Cevap

192
Using the identity that a3+b3+c3=3abca^3 + b^3 + c^3 = 3abc whenever a+b+c=0a + b + c = 0, both the numerator and denominator can be factored directly. Factoring the difference of squares in the numerator yields 3(x−y)(x+y)(y−z)(y+z)(z−x)(z+x)3(x - y)(x + y)(y - z)(y + z)(z - x)(z + x). Dividing this by the factored denominator 3(x−y)(y−z)(z−x)3(x - y)(y - z)(z - x) simplifies the expression to (x+y)(y+z)(z+x)(x + y)(y + z)(z + x). Substituting x=5x = 5, y=3y = 3, and z=1z = 1 yields (8)(4)(6)=192(8)(4)(6) = 192.

Adım Adım Çözüm

1
Use the conditional cubic identity a+b+c=0  ⟹  a3+b3+c3=3abca + b + c = 0 \implies a^3 + b^3 + c^3 = 3abc on the denominator.
Denominator becomes 3(x−y)(y−z)(z−x)3(x - y)(y - z)(z - x).
The sum of the three terms (x−y)+(y−z)+(z−x)(x - y) + (y - z) + (z - x) equals 0.
2
Apply the same identity to the numerator.
Numerator becomes 3(x2−y2)(y2−z2)(z2−x2)3(x^2 - y^2)(y^2 - z^2)(z^2 - x^2).
The sum of the squared difference terms (x2−y2)+(y2−z2)+(z2−x2)(x^2 - y^2) + (y^2 - z^2) + (z^2 - x^2) also equals 0.
3
Factor each difference of squares in the numerator.
Numerator becomes 3(x−y)(x+y)(y−z)(y+z)(z−x)(z+x)3(x - y)(x + y)(y - z)(y + z)(z - x)(z + x).
Using the difference of squares identity u2−v2=(u−v)(u+v)u^2 - v^2 = (u - v)(u + v) on each term.
4
Simplify the fraction by dividing the common factors in the numerator and denominator.
E(x,y,z)=(x+y)(y+z)(z+x)E(x, y, z) = (x + y)(y + z)(z + x).
The factors 33, (x−y)(x - y), (y−z)(y - z), and (z−x)(z - x) cancel out completely.
5
Evaluate the simplified product for x=5x = 5, y=3y = 3, and z=1z = 1.
(5+3)(3+1)(1+5)=8×4×6=192(5 + 3)(3 + 1)(1 + 5) = 8 \times 4 \times 6 = 192.
Direct evaluation after algebraic simplification.

Anahtar Kavram

Simplifying rational expressions involving sum of cubes identity a3+b3+c3=3abca^3 + b^3 + c^3 = 3abc when a+b+c=0a + b + c = 0 and difference of squares factoring.
Soru 20Soru →
For all real numbers xx and yy such that x≠yx \neq y, x≠−yx \neq -y, and x2+y2≠0x^2 + y^2 \neq 0, which of the following expressions is equivalent to
x4−y4x3−x2y+xy2−y3−2xyx+y\frac{x^4 - y^4}{x^3 - x^2 y + x y^2 - y^3} - \frac{2 x y}{x + y}
Cevabı ve açıklamayı göster

Cevap: x2+y2x+y\frac{x^2 + y^2}{x + y}

Cevap

x2+y2x+y\frac{x^2 + y^2}{x + y}
Factoring x4−y4x^4 - y^4 as (x−y)(x+y)(x2+y2)(x - y)(x + y)(x^2 + y^2) and x3−x2y+xy2−y3x^3 - x^2 y + x y^2 - y^3 as (x−y)(x2+y2)(x - y)(x^2 + y^2) simplifies the first term to x+yx + y. Combining x+yx + y with −2xyx+y-\frac{2xy}{x+y} over the common denominator (x+y)(x + y) gives (x+y)2−2xyx+y=x2+y2x+y\frac{(x+y)^2 - 2xy}{x+y} = \frac{x^2 + y^2}{x+y}.

Adım Adım Çözüm

1
Factor the numerator and denominator of the first rational expression
Numerator: x4−y4=(x2−y2)(x2+y2)=(x−y)(x+y)(x2+y2)x^4 - y^4 = (x^2 - y^2)(x^2 + y^2) = (x - y)(x + y)(x^2 + y^2). Denominator: x3−x2y+xy2−y3=x2(x−y)+y2(x−y)=(x−y)(x2+y2)x^3 - x^2 y + x y^2 - y^3 = x^2(x - y) + y^2(x - y) = (x - y)(x^2 + y^2).
Factoring allows for cancellation of common factors in rational expressions.
2
Simplify the first rational expression by canceling common terms
(x−y)(x+y)(x2+y2)(x−y)(x2+y2)=x+y\frac{(x - y)(x + y)(x^2 + y^2)}{(x - y)(x^2 + y^2)} = x + y.
Since x≠yx \neq y and x2+y2≠0x^2 + y^2 \neq 0, the common terms (x−y)(x - y) and (x2+y2)(x^2 + y^2) are non-zero and can be divided out.
3
Subtract the second expression using a common denominator
(x+y)−2xyx+y=(x+y)2x+y−2xyx+y=(x+y)2−2xyx+y(x + y) - \frac{2xy}{x + y} = \frac{(x + y)^2}{x + y} - \frac{2xy}{x + y} = \frac{(x + y)^2 - 2xy}{x + y}.
Combining terms under the common denominator (x+y)(x + y) enables algebraic reduction.
4
Expand the squared binomial in the numerator and simplify like terms
\frac{x^2 + 2xy + y^2 - 2xy}{x + y} = \frac{x^2 + y^2}{x + y}.
Expanding (x+y)2=x2+2xy+y2(x + y)^2 = x^2 + 2xy + y^2 allows the +2xy+2xy and −2xy-2xy terms to cancel out.

Anahtar Kavram

Simplifying rational expressions using polynomial factoring (difference of squares and grouping) and common denominators.
Tahmini Süre:2m 0s
Sayfa 1 / 2Sonraki
Simplifying and Factoring Algebraic Expressions Alıştırma Soruları — GRE General Test | Examkin