Some math genius please help me!?

Question

I'm having a problem with these two:

Given:
f(x) = (3/x^2)-5
g(x) = sqrt(2x+7)

Let p(x) = f(g(x)) and q(x) = g(f(x))

1. Whats p(x) = ?
2. Whats q(x) = ?

Answer 1

1.

f(x) = (3 / x²) - 5

g(x) = √(2x + 7)

p(x) = f(g(x))

Substitute g(x) = √(2x + 7) in the p(x)

p(x) = f(√(2x + 7) = f(t) = (3 / t² - 5)

Therefore p(x) = (3 / 2x + 7) - 5

p(x) = (3 - 10x - 35) / 2x + 7

p(x) = -(10x + 32) / 2x + 7.

Answer 2

2.

f(x) = (3 / x²) - 5

g(x) = √(2x + 7)

q(x) = g(f(x))

Substitute f(x) = (3 / x²) - 5 in the q(x)

q(x) = g((3 / x²) - 5)) = g(t) = √2t + 7

Therefore q(x) = (√2((3 / x²) - 5) + 7).