I. x2 + 3x – 40 = 0 x2 + 8x – 5x – 40 = 0 x(x + 8) – 5(x + 8) = 0 x = 5 and x = –8 II. y2 – 2y – 80 = 0 y2 – 10y + 8y – 80 = 0 y(y – 10) + 8(y – 10) = 0 y = 10 or –8 From the two equations of x and y, it is clear that there is no relation between x and y.