Answer:
so to solve it u wanna take y2-y1 and x2-x1 so 4-2/4-1= 2/3 so basically how u know what to do is remember that
xy xy
(1,2) and (4,4). so when you take y2-y1 and x2-x1 u don't get that numbers wrong so your equation is y=2/3x
hope I explained it well enough for u to understand