persamaan garis lurus yang melalui titik (-3,8) dan (4,5)

(y-y1)/(y2-y1) = (x-x1)/(x2-x1)
(y-8)/(5-8) = (x+3)/(4+3)
(y-8)/(-3) = (x+3)/7
7y-56 = -3x-9
3x+7y = 47