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If x³ + 3x² + k, and x - (2x-2) is a factor of f(x), then what is the value of k?

User Brad Boyce
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1 Answer

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Final answer:

To find the value of k, we need to determine the value of x when the expression x - (2x-2) is a factor of f(x). By setting the expression equal to zero and solving for x, we find that x = 0 or x = 1. Substituting these values into f(x), we can find the corresponding values of k.

Step-by-step explanation:

To find the value of k, we need to determine the value of x when the expression x - (2x-2) is a factor of f(x). This means that when we substitute x - (2x-2) into f(x), it should equal zero.

So, we have (x - (2x-2))(x^3 + 3x^2 + k) = 0. Expanding this expression, we get x^4 - 2x^3+2x - 2x^2 + 4 = 0.

To make sure the above equation is equal to zero, the coefficient of the x term must be zero. Therefore, -2x^3 + 2x = 0. Solving for x, we have x = 0 or x = 1.

Substituting x = 0 into f(x), we get 0^3 + 3(0)^2 + k = 0 + 0 + k = 0, therefore, k = 0.

Substituting x = 1 into f(x), we get 1^3 + 3(1)^2 + k = 1 + 3 + k = 0, therefore, k = -4.

User Ashok Shah
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