If you and your son are graphing liner equations, then all you need to do is make a table, selecting different values for x and calculating for y. For example:
If your equation were y = 3x - 1 then you could choose 0 for x and then y would equal -1 and your solution set would include (0, -1) because of this: 3 times 0 is 0 and 0 minus -1 is -1. You could choose 1 for x and then your value for y would be 2 and your set would include (1, 2) because 3 times 1 is 3 and 3 minus 1 is 2....
You would solve your equation in the same manner. I hope this helps and good luck!
