Okay, I know this looks intimidating but don't worry, it isn't that hard! All you need to do is take any two points on the line, we'll do (-3, 0) and (0,6), choose one to be x1 and y1, and then the other to be x2 and y2, it doesn't matter which one you decide to choose. We'll use (-3,0) as x1 and y1 then (0,6) as x2 and y2, now just use the formula, which is y2 - y1 / x2 - x1, to use this take y2(6) and y1(0) and subtract 6 - 0, which equals six. Then we'll use x2(0) - x1(-3) which equals 3, so now, you take y2 - y1 /x2 - x1 and turn it into 6/3, and you get two, hope this helped you!