Question

Desenvolva e Reduza (x+1)²-(x-1)²

Answer 1

(x+1)²-(x-1)² =
x² + 2x +1 - (x² - 2x +1) = 
x² + 2x + 1 - x² + 2x - 1   
x² - x² +2x +2x +1 - 1
 4x

Answer 2

(x+1) (x+1)- (x-1) (x-1)
x²+x+x+1-(x²-x-x+1)
x²+2x+1-x²+x+x-1=
4x