diketahui f(x)=2x-7 dan g(x)=9-4x tentukan (fof(x) dan (gog) (x) ?

fof(x)=f(f(x)
=f(2x-7)
=2(2x-7)-7
=4x-14-7
=4x-21

gog(x)=g(g(x))
=g(9-4x)
=9-4(9-4x)
=9-36+16x
=-27+16x