M = Y2 - Y1 / X2 - X1 (slope formula) Let's plug in some x variables, and figure out our y variables. Your line: X - 4y = 8 x y 8 0 0 -2 Let's use (0, -2) and (8, 0) in our slope formula. M = 0 - (-2) / 8 - 0 m = 2 / 8 m = 1 / 4 Remember, slope is rise over run. So, if you were to plot these coordinates as well, you should see your line go up 1, and over 4.