Functions of Operations

Question

KEY

f(x)=2x+1

g(x)=3x+4

h(x)=3x^2

k(x)=x^2-4x

1) (h of f)(3)

looked up answer: 147

2) (g of f)(-4)

looked up answer: -17

I wanna know step by step please

Answer 1

f(x)= 2x+1

f(-4)= 2(-4)+1 =-8+1=-7

h(x)=3x^2

h(f(x)) = h(2x+1)

h(-7)=h(f(-4))= h(2(-4)+1) = 3(-7)^2 = 3(49)=147

g(x)=3x+4

g(f(x)) = g(2x+1)

g(f(-4))= g(2(-4)+1) = g(-8+1)=g(-7) = 3(-7)+4 =-21+4= -17