1. The problem statement, all variables and given/known data find a formula for f-1 when f is defined by f(x) = 3x+5/x-4 2. Relevant equations 3. The attempt at a solution Here is what I've done so far: First I switch the x and the y so I get x=3y+5/y-4 x(y-4)=3y+5 xy-4x=3y+5 xy=3y+4x+5 xy-3y=4x+5 y-3y=4x+5/x -2y=4+5 I don't know what else to do. No matter what I try I always end up deleting a variable.