Using factor theorem, show that g(x) is a factor of p(x), when
p(x)=3x3+x2−20x+12,g(x)=3x−2
p(x)=3x3+x2−20x+12g(x)=3x−2x=23
If p(x) is a multiple of g(x), the remainder will be zero.
p(23)=3(23)3+(23)2−20(23)+12=89+49−403+12=129−403+12=43−403+363=4−40+363=0
Therefore p(x) is a multiple of g(x)