You can
put this solution on YOUR website!f^-1 means to take the inverse.
The process is as follows:
1. change f(x) to y (they are the same anyways...)
2. swap x for y and y for x.
3. solve for y
4. change y to f^-1(x).
5. done
For you problem,
1. y=7x+2
2. x=7y+2
3. y=(x-2)/7
4. f^-1(x)=(x-2)/7
