Find f(g(x)) if f(x) = 5x and g(x) = 3x-12

Answer 1

In f(x)= 5x substitute the expression of g(x) everywhere you see an x.

so instead of f(x)=5x we would have f(g(x))= 5*(3x-12) . The 3x-12 takes the place of the x in the original.

If you want you can simplify : f(g(x))= 15x-60 = 15(x-4)