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Zorluk: ZorEquivalent Algebraic Expressions

If the expression 3x38x2+kx63x2\frac{3x^3 - 8x^2 + kx - 6}{3x - 2} is equivalent to x22x+3x^2 - 2x + 3 for all x23x \neq \frac{2}{3}, where kk is a constant, what is the value of kk?

Cevap: 13

Cevap

13
By multiplying both sides of the equation by 3x23x - 2, the rational expression simplifies to a polynomial identity: 3x38x2+kx6=(x22x+3)(3x2)3x^3 - 8x^2 + kx - 6 = (x^2 - 2x + 3)(3x - 2). Expanding the right side yields 3x38x2+13x63x^3 - 8x^2 + 13x - 6. Since the two polynomials are equivalent, their corresponding coefficients must be equal, meaning the coefficient of the linear term, kk, must be equal to 1313.

Adım Adım Çözüm

1
Multiply both sides of the equivalence by the denominator (3x2)(3x - 2)
3x38x2+kx6=(x22x+3)(3x2)3x^3 - 8x^2 + kx - 6 = (x^2 - 2x + 3)(3x - 2)
To clear the fraction and align the polynomial expressions for coefficient comparison.
2
Expand the right side of the equation using the distributive property
3x38x2+13x63x^3 - 8x^2 + 13x - 6
To obtain the expanded form of the polynomial so that we can identify the coefficients of each term.
3
Equate the corresponding coefficients of the linear xx terms on both sides of the equation
k=13k = 13
Since the two expressions are equivalent for all values of xx, their coefficients for each corresponding power of xx must be equal.

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Equivalent Algebraic Expressions
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