Question

Confirm that f and g are inverses by showing that f(g(x)) = x and g(f(x)) = x.
f(x) = 9x + 3 and g(x) =(x-3)/9
please help.

Answer 1

this is what i have so far
f(g(x))= 9((x-3)/9)+3
(9x-27)/9 + 3
(9x-24)/9

g(f(x))= ((9x+3)-3)/9
9x/9
does this mean theyre not inverses?

Answer 2

There's a small mistake you made:
\[\begin{align*}f(g(x))&=9\left(\frac{x-3}{9}\right)+3\\
&=\frac{9x-27}{9}+3\\
&=\frac{9x-27}{9}+\color{red}{\frac{27}{9}}\\
&=\frac{9x}{9}\\
&=x
\end{align*}\]

Answer 3

so they are inverses

Answer 4

yes

Answer 5

okay thank you :)