Question

Let f(x) = x – 4 and g(x) = 3x + 6. What is f(g(x)) ?

Answer 1

plug g(x) instead of x :

(3x + 6) - 4

Answer 2

you have to put the g(x) into the f(x)

Answer 3

Then what, I'm still confused

Answer 4

Plug the whole g(x) in for the x in f(x):

(3x + 6) - 4
so 3x + 2

Answer 5

Oh, okay.

Answer 6

Well think of it this way. if x=5, then f(x) = 5-4, right?

Try and now think of x=g(x) which is just another function. So where ever an x is in the f(x) function, you must place in the function from g(x).