Question

Show that (x+3) is a factor of p(x) = 69+11x-x2+x3.

Answer 1

f(-3)=69+11×(-3)-(-3)^2+(-3)^3
f(-3)=69-33-9-27
f(-3)=69-69
f(-3)=0
yes

Answer 2

x+3
x=-3
p(x)=x^3-x^2+11x+69
p(-3)=(-3)^3-(-3)^2+11(-3)+69
=-27-9-33+69
=-69+69
=0
therefore (x+3)is a factor