Math
posted by Neil on .
1.Let f(x)= x^2  5 and g(x)= 3x^2. Find g(f(x)).
2. Let f(x)= x^2  4 and g(x) 3x^2. Find f(g(x)).

g(x)= 3x^2
g(f(x))= 3(x^24)^2
6(x^24)(2x)
6x^224 (2x)
12x^348x
12x(x^2+4)
f(g(x))= (3x^2)^24
2(3x^2)(6x)4
6x^2(6x)4
36x^34
4(9x^31) 
I think you're doing it wrong, because I am not getting those answers. I got answer choices.

Neil  for heaven's sakes! If you have answer choices, please post them along with your problem!

1. Let f(x)= x^2  5 and g(x)= 3x^2. Find g(f(x)).
A. 3x^4  30x^2 + 75
B. 3x^4  15
C. 9x^4
D. 3x^4  4
2. Let f(x)= x^2  4 and g(x)= 3x^2. Find f(g(x)).
F. 3x^4 + 12
G. 3x^4 + 24x^2  48
H. 9x^4  4
I. 3x^4  4