(2x-1) (2x+1) - х (1-х) =2х(х+1)

Question

(2x-1) (2x+1) - х (1-х) =2х(х+1)

Answer 1

(2х-1)(2х+1)-х(1-х)=2х(х+1)
4х²-1-х+х²=2х²+2х
4х²+х²-2х²-х-2х=1
3х²-3х=1