Is that supposed to be 2x^2+3 and x+7? What do the 3 and seven do in each equation?

Actually it doesn't matter, I'll just tell you what it means. g(f(x)) means you plug in the whole function f(x) into the variable in g(x). g(f(x))= (f(x)) then plus or minus 7. f(g(x))=2(g(x))^2 then plus or minus 3. Got it?

I'll give an example.

Let:

p(x) = 4x + 3

q(x) = \frac{1}{x}

Then,

q(p(x)) = q(4x+3) = \frac{1}{4x+3}

p(q(x)) = p(\frac{1}{x}) = 4(\frac{1}{x}) +3 = \frac{4}{x} + 3

And kpg0001, I would suggest you make use of paragraphing when answering. I just read the other thread "Trigonometry and bearing' and blocks of text are not that easy to read. Thanks! :)