Пошаговое объяснение:
(x-1)(x+2) - (x-2)(x+2) = 10,
(х+2)(х-1 - х+2) = 10,
(х+2) * 1 = 10,
х + 2 = 10,
х = 10 - 2,
х = 8,
или:
(x-1)(x+2) - (x-2)(x+2) = 10,
х² + 2х - х - 2 - х² - 2х + 2х + 4 = 10,
х - 2 + 4 = 10,
х = 10 + 2 - 4,
х = 8,
(x-4)(x+7) = x² - 2,
х² + 7х - 4х - 28 = х² - 2,
3х - 28 = -2,
3х = 28 - 2,
3х = 26,
х = 8 2/3