Question

If (x + 3) completely divides (3x^2 + kx – 6), then the value of k is,1)7 2)-7 3)-3 4)3

Answer 1

Answer:

let f(x)=3x²+kx-6

since, x+3 completely divides f(x)

so,f(-3)=0

3(-3)²+k(-3)-6=0

3×9-3k-6=0

27-6-3k=0

21-3k=0

3k=21

k=7