Question

find g(f(x)) if f(x)=2x and g(x)=x^2

Answer 1

g(f(x)) = 4x²

substitute x = f(x) into f(x)

g(f(x)) = g(2x) = (2x)² = 4x²

Answer 2

$g(f(x))=(2x)^2=4x^2$