Question

2. If xcube+6xsquare+ 4x +k is exactly divisible by x+2,then k=
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Answer 1

Answer:

k = - 8.

Step-by-step explanation:

f(x) = x³ + 6x² + 4x + k

since this is exactly divisible by x+2, the result should be zero when x is substituted with -2.

f(-2) = (-2) ³ + 6 (-2)² + 4 (-2) + k = 0

            - 8+ 24 - 8 + k = 0

            => k = - 8.