Question 63216
Let f(x)=7x an g(x)= 2x^2-9. find the following: 

(fog)(x) (gof)(x) (fog)(2) and (gof)(-1)

not sure what i am doing,,,thanks for your help

Solution:

Given fog(x) = f(g(x)) = f(2x^2 -9) = 7(2x^2 -9) = 14x^2 -56

g0f(x) = g(f(x) = g(7x) = 2(7x)^2 -9 = 2(49x^2) - 9 = 98x^2-9


Fog(2) = 14(2)^2 - 56 = 0 

gof(-1) = 98(-1)^2 - 9 = 98 - 9 = 89