Multiplying Polynomials

27 soru

Soru 21Soru →

If the polynomial expression (3x−5)(3x - 5) is multiplied by the expression (Ax2+2x−7)(Ax^2 + 2x - 7), the resulting simplified polynomial has an x2x^2 coefficient of −19-19. What is the value of the constant AA?

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Cevap: 5

Cevap

5
The x2x^2 terms in the product of (3x−5)(3x - 5) and (Ax2+2x−7)(Ax^2 + 2x - 7) are generated by multiplying the xx terms together (3x⋅2x=6x2)(3x \cdot 2x = 6x^2) and by multiplying the constant by the x2x^2 term (−5⋅Ax2=−5Ax2)(-5 \cdot Ax^2 = -5Ax^2). Setting their sum equal to −19x2-19x^2 gives the equation 6−5A=−196 - 5A = -19. Solving for AA yields A=5A = 5.

Adım Adım Çözüm

1
Identify combinations that yield an x2x^2 term
The x2x^2 terms come from multiplying (3x)(3x) by (2x)(2x) and (−5)(-5) by (Ax2)(Ax^2).
To find the coefficient of a specific term without expanding the entire polynomial, only multiply the terms whose exponents sum to the target power.
2
Calculate the partial products
(3x)(2x)=6x2(3x)(2x) = 6x^2 and (−5)(Ax2)=−5Ax2(-5)(Ax^2) = -5Ax^2
These represent the only contributions to the x2x^2 term in the final expanded polynomial.
3
Formulate an equation for the coefficient
6−5A=−196 - 5A = -19
The sum of the partial x2x^2 coefficients must equal the total x2x^2 coefficient given in the problem.
4
Solve the linear equation for AA
−5A=−25→A=5-5A = -25 \rightarrow A = 5
Isolating the variable AA provides the final answer.

Anahtar Kavram

Multiplying Polynomials
Soru 22Soru →

A polynomial P(x)P(x) is defined as the product of the binomial (4x−3)(4x - 3) and the trinomial (−2x2+5x−1)(-2x^2 + 5x - 1). What is the fully expanded and simplified form of P(x)P(x)?

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Cevap: −8x3+26x2−19x+3-8x^3 + 26x^2 - 19x + 3

Cevap

−8x3+26x2−19x+3-8x^3 + 26x^2 - 19x + 3
The correct expression is found by successfully distributing both 4x4x and −3-3 across the trinomial (−2x2+5x−1)(-2x^2 + 5x - 1), maintaining correct exponents and signs, and finally combining the like terms: 20x220x^2 with 6x26x^2, and −4x-4x with −15x-15x.

Adım Adım Çözüm

1
Set up the multiplication using the distributive property.
4x(−2x2+5x−1)−3(−2x2+5x−1)4x(-2x^2 + 5x - 1) - 3(-2x^2 + 5x - 1)
Every term in the first polynomial must be multiplied by every term in the second polynomial.
2
Distribute 4x4x through the trinomial.
4x(−2x2)+4x(5x)+4x(−1)=−8x3+20x2−4x4x(-2x^2) + 4x(5x) + 4x(-1) = -8x^3 + 20x^2 - 4x
Multiply coefficients and add exponents for the variable base.
3
Distribute −3-3 through the trinomial.
−3(−2x2)−3(5x)−3(−1)=6x2−15x+3-3(-2x^2) - 3(5x) - 3(-1) = 6x^2 - 15x + 3
Multiply the constant by each term, carefully applying integer sign rules.
4
Combine the results and group like terms.
−8x3+(20x2+6x2)+(−4x−15x)+3-8x^3 + (20x^2 + 6x^2) + (-4x - 15x) + 3
Grouping terms with the same variable exponent prepares the expression for final simplification.
5
Add the coefficients of the like terms.
−8x3+26x2−19x+3-8x^3 + 26x^2 - 19x + 3
This yields the polynomial in standard form.

Anahtar Kavram

Multiplying polynomials by distributing every term in the first factor to every term in the second, then combining like terms.
Soru 23Soru →

A manufacturer is cutting a square opening out of a rectangular metal panel. The rectangular panel has a length of (4x−1)(4x - 1) inches and a width of (2x+3)(2x + 3) inches. The square opening to be removed has a side length of (x+2)(x + 2) inches. Which of the following expressions represents the total remaining area of the metal panel after the square is removed?

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Cevap: 7x2+6x−77x^2 + 6x - 7

Cevap

The correct expression is 7x2+6x−77x^2 + 6x - 7.
The remaining area is found by subtracting the square's area from the rectangle's area. Multiplying the dimensions (4x−1)(2x+3)(4x - 1)(2x + 3) yields 8x2+10x−38x^2 + 10x - 3. Squaring the dimension (x+2)(x + 2) yields x2+4x+4x^2 + 4x + 4. Subtracting the entire second polynomial requires distributing the negative sign, resulting in 8x2+10x−3−x2−4x−48x^2 + 10x - 3 - x^2 - 4x - 4, which correctly simplifies to 7x2+6x−77x^2 + 6x - 7.

Adım Adım Çözüm

1
Calculate the area of the rectangular panel.
(4x−1)(2x+3)=8x2+12x−2x−3=8x2+10x−3(4x - 1)(2x + 3) = 8x^2 + 12x - 2x - 3 = 8x^2 + 10x - 3
The area of a rectangle is length multiplied by width, which requires multiplying two binomials using the FOIL method.
2
Calculate the area of the square opening.
(x+2)2=(x+2)(x+2)=x2+2x+2x+4=x2+4x+4(x + 2)^2 = (x + 2)(x + 2) = x^2 + 2x + 2x + 4 = x^2 + 4x + 4
The area of a square is its side length multiplied by itself.
3
Subtract the square's area from the rectangle's area.
(8x2+10x−3)−(x2+4x+4)=8x2+10x−3−x2−4x−4=7x2+6x−7(8x^2 + 10x - 3) - (x^2 + 4x + 4) = 8x^2 + 10x - 3 - x^2 - 4x - 4 = 7x^2 + 6x - 7
To find the remaining area, the removed portion must be subtracted. It is critical to distribute the negative sign to every term inside the parentheses being subtracted.

Anahtar Kavram

Multiplying binomials and subtracting polynomials while properly distributing negative signs.
Soru 24Soru →

Which of the following expressions is equivalent to the product of (5x−2)(5x - 2) and (x2−3x−4)(x^2 - 3x - 4)?

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Cevap: 5x3−17x2−14x+85x^3 - 17x^2 - 14x + 8

Cevap

The correct answer is 5x3−17x2−14x+85x^3 - 17x^2 - 14x + 8.
The correct expression is found by systematically distributing each term in the first polynomial to each term in the second. First, multiplying 5x5x by (x2−3x−4)(x^2 - 3x - 4) yields 5x3−15x2−20x5x^3 - 15x^2 - 20x. Next, multiplying −2-2 by (x2−3x−4)(x^2 - 3x - 4) yields −2x2+6x+8-2x^2 + 6x + 8. Finally, combining the like terms (−15x2-15x^2 and −2x2-2x^2 becomes −17x2-17x^2; −20x-20x and 6x6x becomes −14x-14x) results in the simplified polynomial 5x3−17x2−14x+85x^3 - 17x^2 - 14x + 8.

Adım Adım Çözüm

1
Distribute the first term of the binomial, 5x5x, to each term in the trinomial.
5x(x2−3x−4)=5x3−15x2−20x5x(x^2 - 3x - 4) = 5x^3 - 15x^2 - 20x
To expand the polynomials, every term in the first polynomial must be multiplied by every term in the second.
2
Distribute the second term of the binomial, −2-2, to each term in the trinomial.
−2(x2−3x−4)=−2x2+6x+8-2(x^2 - 3x - 4) = -2x^2 + 6x + 8
The second term, along with its negative sign, must also be multiplied by every term in the trinomial.
3
Add the results from Step 1 and Step 2 and combine like terms.
(5x3−15x2−20x)+(−2x2+6x+8)=5x3−17x2−14x+8(5x^3 - 15x^2 - 20x) + (-2x^2 + 6x + 8) = 5x^3 - 17x^2 - 14x + 8
Combining terms with the same variable to the same power fully simplifies the resulting polynomial.

Anahtar Kavram

Multiplying Polynomials using Distribution
Soru 25Soru →

A rectangular garden has a length of (3x−2)(3x - 2) meters and a width of (2x+5)(2x + 5) meters. Inside the garden, a smaller rectangular paved patio is built with a length of (x+4)(x + 4) meters and a width of 2x2x meters. Which of the following expressions represents the total area of the garden that is NOT paved, in square meters?

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Cevap: 4x2+3x−104x^2 + 3x - 10

Cevap

The expression representing the unpaved area is 4x2+3x−104x^2 + 3x - 10.
The correct answer is found by calculating the area of the entire garden and subtracting the area of the patio. First, multiply the dimensions of the garden using the distributive property (FOIL): (3x−2)(2x+5)=6x2+15x−4x−10=6x2+11x−10(3x - 2)(2x + 5) = 6x^2 + 15x - 4x - 10 = 6x^2 + 11x - 10. Next, find the area of the patio by distributing 2x2x: (x+4)(2x)=2x2+8x(x + 4)(2x) = 2x^2 + 8x. Finally, subtract the patio's area from the total area: (6x2+11x−10)−(2x2+8x)(6x^2 + 11x - 10) - (2x^2 + 8x). Make sure to distribute the negative sign to both terms in the second polynomial: 6x2+11x−10−2x2−8x=4x2+3x−106x^2 + 11x - 10 - 2x^2 - 8x = 4x^2 + 3x - 10.

Adım Adım Çözüm

1
Calculate the total area of the garden by multiplying its length and width.
(3x−2)(2x+5)=6x2+15x−4x−10=6x2+11x−10(3x - 2)(2x + 5) = 6x^2 + 15x - 4x - 10 = 6x^2 + 11x - 10
The area of a rectangle is found by multiplying its length by its width.
2
Calculate the area of the paved patio by multiplying its length and width.
(x+4)(2x)=2x2+8x(x + 4)(2x) = 2x^2 + 8x
We need the area of the inner rectangle in order to subtract it from the total area.
3
Subtract the patio's area from the total garden area to find the unpaved area.
(6x2+11x−10)−(2x2+8x)=6x2+11x−10−2x2−8x=4x2+3x−10(6x^2 + 11x - 10) - (2x^2 + 8x) = 6x^2 + 11x - 10 - 2x^2 - 8x = 4x^2 + 3x - 10
The unpaved region is the difference between the total area and the paved area. Note that the negative sign must be distributed to both terms in the second polynomial.

Anahtar Kavram

Multiplying Polynomials
Soru 26Soru →

Determine the value of the missing coefficient by evaluating the problem below.

Aşağıdaki boşlukları doldurun

A rectangular solar panel has a length of (5k−4)(5k - 4) inches and a width of (3k+7)(3k + 7) inches. The area of the panel is represented by the fully expanded polynomial Ak2+Bk+CAk^2 + Bk + C square inches. The value of the coefficient BB is .
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Cevap

23
By multiplying the binomials (5k−4)(5k - 4) and (3k+7)(3k + 7), the expanded expression is 15k2+35k−12k−2815k^2 + 35k - 12k - 28. Combining the middle terms (35k−12k35k - 12k) yields 23k23k. Since the polynomial is in the standard form Ak2+Bk+CAk^2 + Bk + C, the value of BB is 23.

Adım Adım Çözüm

1
Set up the area calculation by multiplying the length and width binomials.
Area = (5k−4)(3k+7)(5k - 4)(3k + 7)
The area of a rectangle is found by multiplying its length by its width.
2
Distribute the terms using the FOIL method (First, Outer, Inner, Last).
15k2+35k−12k−2815k^2 + 35k - 12k - 28
Each term in the first binomial must be multiplied by each term in the second binomial.
3
Combine the like terms in the middle to find the value of BB.
15k2+23k−2815k^2 + 23k - 28
Adding 35k35k and −12k-12k simplifies the polynomial to the standard form Ak2+Bk+CAk^2 + Bk + C.
4
Identify the coefficient BB corresponding to the kk term.
B=23B = 23
The polynomial is 15k2+23k−2815k^2 + 23k - 28, so the coefficient of the kk term is 23.

Anahtar Kavram

Multiplying binomials and combining like terms to find a specific coefficient.
Soru 27Soru →

Which of the following represents the fully simplified product of the polynomials (3a−2b)(3a - 2b) and (4a2+5ab−b2)(4a^2 + 5ab - b^2)?

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Cevap: 12a3+7a2b−13ab2+2b312a^3 + 7a^2b - 13ab^2 + 2b^3

Cevap

The fully simplified product is 12a3+7a2b−13ab2+2b312a^3 + 7a^2b - 13ab^2 + 2b^3.
The correct answer is obtained by distributing each term in the binomial to every term in the trinomial, and then combining the like terms. Multiplying 3a3a by each term yields 12a3+15a2b−3ab212a^3 + 15a^2b - 3ab^2. Multiplying −2b-2b by each term yields −8a2b−10ab2+2b3-8a^2b - 10ab^2 + 2b^3. Adding these together and combining the like terms (15a2b−8a2b=7a2b15a^2b - 8a^2b = 7a^2b and −3ab2−10ab2=−13ab2-3ab^2 - 10ab^2 = -13ab^2) results in the final expression.

Adım Adım Çözüm

1
Distribute the first term of the binomial, 3a3a, to every term in the trinomial.
3a(4a2)+3a(5ab)+3a(−b2)=12a3+15a2b−3ab23a(4a^2) + 3a(5ab) + 3a(-b^2) = 12a^3 + 15a^2b - 3ab^2
This applies the distributive property to begin multiplying the polynomials.
2
Distribute the second term of the binomial, −2b-2b, to every term in the trinomial.
−2b(4a2)−2b(5ab)−2b(−b2)=−8a2b−10ab2+2b3-2b(4a^2) - 2b(5ab) - 2b(-b^2) = -8a^2b - 10ab^2 + 2b^3
This completes the distribution process for all terms.
3
Write out the full expanded expression by combining the results from the previous steps.
12a3+15a2b−3ab2−8a2b−10ab2+2b312a^3 + 15a^2b - 3ab^2 - 8a^2b - 10ab^2 + 2b^3
This provides the complete polynomial before simplification.
4
Group and combine the like terms.
12a3+(15a2b−8a2b)+(−3ab2−10ab2)+2b3=12a3+7a2b−13ab2+2b312a^3 + (15a^2b - 8a^2b) + (-3ab^2 - 10ab^2) + 2b^3 = 12a^3 + 7a^2b - 13ab^2 + 2b^3
Combining terms with identical variable parts simplifies the expression to its final standard form.

Anahtar Kavram

Multiplying a binomial by a polynomial requires distributing every term in the first polynomial to every term in the second polynomial, carefully tracking negative signs, and then combining any like terms.
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Multiplying Polynomials Alıştırma Soruları — Armed Services Vocational Aptitude Battery (ASVAB) — Sayfa 2 | Examkin