So for me, how I would do it is move the variables and numbers to one side. So we have the equation 3x-3=2/5x+7. So you would subtract 2/5x to the left side and add 3 to the right side. The equation will then turn out to be 3x-2/5x=7+3. Much more easier right? So just simplify both side, and you will get 13/5x=10. In order to isolate x, you have to divide 13/5 in both side, leaving x= 3 11/13 or 50/13. You can always plug the answer back in to double check :)