Find the inverse of a function with two variables

To find the inverse of a problem you have to do the opposite of the number on both side for example 4x+6=-4x-2 you Have to subtract the +4 which is the inverse of adding on the left on both side which equals 6=-8x-2 we did this because we have LIKE TERMS then you will add the -2 on the right which is the inverse of subtracting and your answer will be 8=8x the final step the 8x are being multiply so we have to divide them in the last step you don't need like terms the answer will be x=1 because 8 divided by 8 on both side is 1.

Where is the diagram?