Question

qual é a resposta de
(x - 6).(x + 7)
e
(5x + 7y).(5x - 7y)

Answer 1

 

A) (x - 6) • (x + 7)

x² + 7x - 6x - 42

x² + x - 42

B) (5x + 7y) • (5x - 7y)

25x² - 35y + 35y - 49y²

25x² - 49y²

Answer 2

(x - 6)(x + 7)

x(x + 7) - 6(x + 7)

x² + 7x - 6x - 42

x² + x - 42

(5x + 7y)(5x - 7y)

5x(5x - 7y) + 7y(5x - 7y)

25x² - 35xy + 35xy - 49y²

25x² - 49y²

. .

Espero Ter Ajudado !!