calculate the slope of a line throught two points.1.(4, 8) and (6, 12)2.(-3, 2)and (5, -1) 3.(0, 11) and(6, 14)4.(-8, -1) and (-6, -4) 5.(4,9)and (7, 9) 6.(3, 4)and (4, -18)