(2х-1)в квадрате =(1-х)в квадрате

(2x - 1)² = ( 1 - x)²
(2x - 1)(2x - 1) = (1 - x)( 1 - x)
4x² - 2x - 2x + 1 = 1 - 2x + x²
4x² - 4x + 1 = 1 - 2x + x²
4x² - 4x + 1 - 1 + 2x - x² = 0
3x² - 2x =0
D = b² - 4ac = (-2)² - 4 × 3 × 0 = 4
x₁ = 2 + 4 / 6 = 6/6 = 1
x₂ =2 - 4 / 6 = - 2/6 = - 1/3