2x² - x - 28 = 0 dengan x1 < x2 Tentukan nilai 2x1 + x2!

2x² - x - 28 = 0
(2x + 7)(x - 4) = 0
2x + 7 = 0
2x = -7
x1 = -7/2 = -3,5
x - 4 = 0
x2 = 4
2x1 + x2 = 2(-3,5) + 4 = -7 + 4 = -3