# Algebra

posted by .

Help please! I got so far with this and stopped because of confusion. Here is what I have so far.

Let f(x) = 6/x-1 and g(x) = 1 + 3/x find the composite function of (fog)(x)

(fog)(x) = f (g(x))

=f (1+3/x)

=6/x-1

????

• Algebra -

ok up to
=f (1+3/x) , then
= 6/[1+3/x - 1]
= 6/(3/x)
= 2x

• Algebra -

So 2x would be the answer? I was thinking about including the 1+3/x-1 in the middle of the problem... So then 2x is it then I suppose?

• Algebra -

It is a good idea to check you final answer by picking some value of x

e.g let x = 3
g(3) = 1+3/3 = 2
then f(g(3)) = f(2) = 6/(2-1) = 6

my expression was f(g(x)) = 2x
then f(g(3)) = 2(3) = 6

Even though this does not "prove" that I have the right answer, there is a very high probability that it is correct.

## Similar Questions

1. ### Algebra

When Let f (x) = x^2 – 3x + 8 and g(x) = x – 5 Find Find the composite function of (fºg)(x) and simplify Find (fºg)(2) Find the composite function (gºf)(x)
2. ### Algebra

Very confused, and in need of help! I got 10 problems like this...Thanks! Let f(x) = 6/x-1 and g(x)= 1+3/x Please find the composite function (fog)(x)
3. ### Algebra

Let f(x) = 6/x-1 and g(x) = 1+3/x. Please find the composite function of (fog)(x)
4. ### Composite Functions

f(x)=(7x+28)/(x-3) and g(x)=(3x+28)/(x-7) Find: (fog)(x) (gof)(x) (fog)(-1)
5. ### college algebra--need help please!!

find the domain of the composite function fog. f(x)= 2/x-3; g(x)= 7/x please show all work.
6. ### college algebra--I really need help!!

Find the domain of the composite function FOG f(x)= 2/x-3; g(x)= 7/x please show work so I can undestand