Question

show that (x+2) is a factor of xcube - 4x²-2x+20​

Answer 1

Step-by-step explanation:

given p(x)=x^3-4x^2-2x+20

g(x)=x+2

x+2=0then x=-2

if g(x) is factor of p(x) then p(-2)=0

put x=-2 in the p(x)

=(-2)^3-4(-2)^2-2(-2)+20

=-8-16+4+20

=-24+24

=0

as p(x)=p(-2)=0

so (x+2) is a factor of given p(x)