(2x-1)²-(2x+1)•(2x-1)=
4x^2 - 4x + 1 - (4x^2 - 1) = = 4x^2 - 4x + 1 - 4x^2 + 1 = = - 4x + 2 = = - 2(2x - 1)
Решите задачу: