So to start you should get x and y on the same side and get the numbers on one side. Then you should cancel out a variable. Because both y’s are 1 and they are opposite charges they will both cancel out to 0. Then add what is remaining which is the 2x and the 3x and equal that to +9-4 which equals 5. You want x to be all by itself so you would divide both sides by 5 and get that x=1. Then you would just substitue and solve for y. Hope this helped!