Given the functions g(x) = 3/(x - 1), f(x) = (x - 1)/(x - 3) what is g(f(x))?

1 Answer
Dec 11, 2015

(3x-9)/2

Explanation:

To find g(f(x)), take f(x), or color(blue)((x-1)/(x-3)), and plug it in for x in g(x), or 3/(color(blue)(x)-3).

You get that

g(f(x))=3/(color(blue)((x-1)/(x-3))-1)

Multiply everything by x-3.

=3/((x-1)/(x-3)-1)((x-3)/(x-3))=(3(x-3))/((x-1)-1(x-3))

=(3(x-3))/(x-1-x+3)=(3x-9)/2