Question

responda me 2)(x+1).(x-1)-x(x+1) 3) (a+b)²-(a-b)²

Answer 1

2) (x + 1) . (x - 1) - x(x + 1)
(x +1) . [(x - 1) - x]
(x + 1) . (-1)
-x -1

3) (a + b)² - (a - b)² 
[(a + b) + (a - b)] . [(a + b) - (a - b)]
(2a) . (2b)
4ab