Question

if (x+3) is a factor of f(x)=x ^​3​​+ qx^2 -4x-12 then find the value of q.

Answer 1

given factor
so remainder should turn 0
and -12-15+9q=0
-27+9q=0
9q=27
q=3

Answer 2

divided by (x+3)..
x+3=0..
x=-3..
putting the value of x =-3..f(-3)
x³+qx²-4x-12
(-3)³+q(-3)²-4(-3)-12..
-27+9q+12-12..
-27+9q=0..
9q=27..
q=27/9
q=3..