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Value of k for which x + k is a factor o...

Value of k for which x + k is a factor of the polynomial `x^(3)+kx^(2)-2x+k+4` is

A

`-(4)/(3)`

B

`(3)/(4)`

C

`-(3)/(4)`

D

`(4)/(3)`

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The correct Answer is:
To find the value of \( k \) for which \( x + k \) is a factor of the polynomial \( P(x) = x^3 + kx^2 - 2x + k + 4 \), we can follow these steps: ### Step 1: Understand the Factor Condition Since \( x + k \) is a factor of the polynomial, it implies that substituting \( x = -k \) into the polynomial should yield zero. This means that \( P(-k) = 0 \). ### Step 2: Substitute \( x = -k \) into the Polynomial We substitute \( x = -k \) into the polynomial: \[ P(-k) = (-k)^3 + k(-k)^2 - 2(-k) + k + 4 \] ### Step 3: Simplify the Expression Now, we simplify the expression: \[ P(-k) = -k^3 + k(k^2) + 2k + k + 4 \] \[ = -k^3 + k^3 + 2k + k + 4 \] ### Step 4: Combine Like Terms Combine the like terms: \[ = 0 + 3k + 4 \] \[ = 3k + 4 \] ### Step 5: Set the Expression Equal to Zero Since \( P(-k) = 0 \), we set the expression equal to zero: \[ 3k + 4 = 0 \] ### Step 6: Solve for \( k \) Now, we solve for \( k \): \[ 3k = -4 \] \[ k = -\frac{4}{3} \] ### Final Answer Thus, the value of \( k \) for which \( x + k \) is a factor of the polynomial is: \[ \boxed{-\frac{4}{3}} \] ---

To find the value of \( k \) for which \( x + k \) is a factor of the polynomial \( P(x) = x^3 + kx^2 - 2x + k + 4 \), we can follow these steps: ### Step 1: Understand the Factor Condition Since \( x + k \) is a factor of the polynomial, it implies that substituting \( x = -k \) into the polynomial should yield zero. This means that \( P(-k) = 0 \). ### Step 2: Substitute \( x = -k \) into the Polynomial We substitute \( x = -k \) into the polynomial: \[ ...
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