Question

If x cube+6x square+kx+6 is exactly divisible by(x+2), then k=???

Choose the correct one

a) -6

B) -7

C) -8

D)11

Kindly explain

Answer 1

X³+6x²+kx+6 is divisible by (x+2) that means x+2 is a factor
So x+2=0
X=-2 is root of the equation.
Put x= -2 in the equation and it should be equal to zero
(-2)³+6(-2)²+k(-2)+6= 0
-8+24-2k+6=0
2k=22
K= 11
So option D is correct .