You need to define h(x) to find its inverse.
The general answer is to replace h(x)= with y=. Then you make x the subject of the equation so that you get x= some function of y. That function is the inverse of the original function.
Example: h(x)=2x+5. Write y=2x+5. Now solve for x: x=(y-5)/2 so h⁻¹(y)=(y-5)/2 and h⁻¹(x)=(x-5)/2 is the inverse of h(x).
