Question

If (x-3) is a factor of p(x)=x³-kx²+(k+1)x-12 find the value of x

Answer 1

x-3=0 x=3
p(x)=x^3-kx^2+(k+1)-12
p(3)=3^3-k(3)^2+(k+1)3-12
p(3)=27-9k+3k+3-12
=-3k+18=0
-3k=-18
3k=18
k=18/3
k=6

Answer 2

k =6 is the right answer