How would I do this problem algebraically

[moronatmath]

find the inverse of
f(x)=9x+9
Easy enough to just do some plugging in.
F^-1(x)=(x-9)/9

How would I do this problem (the other way) algebraically?

 

[stapel]

The usual process is, roughly, as follows:

. . . . .1) Rename "f(x)" as "y".
. . . . .2) Solve for "x=".
. . . . .3) Switch "x" and "y".
. . . . .4) Rename the new "y" as "f^-1(x)".

Hope that helps a bit.

Eliz.