Persamaan kuadrat yang mempunyai akar-akar-1/2 dan 1/5
x1 = -1/2
x2 = 1/5
Persamaan kuadrat
(x – x1)(x – x2) = 0
(x – (-1/2))(x – 1/5) = 0
(x + 1/2)(x – 1/5) = 0
x² + 1/2 x – 1/5 x – 1/10 = 0
————————————— kalikan 10
10x² + 5x – 2x – 1 = 0
10x² + 3x – 1 = 0