Resposta :
1° Passo:
(x - 1)² - (x + 1)²=
[(x - 1) . (x - 1)] - [(x + 1) . (x+1)]=
[x² - 2x + 1²] - [x² + 2x +1²]=
x² - 2x + 1 - x² - 2x - 1=
-4x=
x= -4
(x - 1)² - (x + 1)²=
[(x - 1) . (x - 1)] - [(x + 1) . (x+1)]=
[x² - 2x + 1²] - [x² + 2x +1²]=
x² - 2x + 1 - x² - 2x - 1=
-4x=
x= -4