с 3 умоляю!. Полностю надо росписать

а) (x-1)(x+1) - x(x-2) = 0

x² - 1 - x² + 2x = 0

-1 + 2x = 0

2x = 1

x = 0,5

б) (3x+1)²-9(x+1)(x-1) = 0

9x²+6x+1 - 9(x²-1) = 0

9x²+6x+1-9x²+9 = 0

6x + 10 = 0

6x = -10

x = -10/6 = -1 4/6 = -1 2/3

Объяснение:

а)(2+а)^2, =(2+а)(2+а)=

=4+2а+2а+а^2=

=4+4а+а^2

б) (2х-1)^2=

=(2х-1)(2х-1)=

=(4х^2-2х-2х+1)=

=4х^2-4х+1