( х - 1 ) ( х - 2 ) = ( 3х + 1 ) ( х - 2 )
х² - 2х - х + 2 = 3х² - 6х + х - 2
х² - 2х - х + 2 - 3х² + 6х - х + 2 = 0
-2х² + 2х + 4 = 0 | ÷ (-2)
х² - х - 2 = 0
Д = 1 - 4 × 1 × (-2) = 1 + 8 = 9. √9 = 3.
х1 = 1 + 3 / 2 = 4/2 = 2.
х2 = 1 - 3 / 2 = -2/2 = -1.
Ответ : -1 ; 2.
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