The slope formula is y2-y1/x2-x1, this is considered rise over run. Simply subtract the y2 variable from the y1 variable, 1-(-1) =2 and then subtract the x2 variable from the x1 variable, 2-1 = 1. From there, ride (y) is on top and run(x) is on the bottom. Divide 2/1 which equal 2. The slope of this line is 2.
Hope this helped :)
