Question

simplifique as expressões (7x+y)'2-(7x+y).(7x-y)

*ME AJUDA PFV

Answer 1

$(7x+y)^2 - (7x+y)(7x-y) = (7x)^2+2 \cdot 7x \cdot y + y^2 - ((7x)^2-y^2)$

$= 49x^2+14xy + y^2 - (49x^2-y^2)$

$= 49x^2+14xy + y^2 - 49x^2+y^2$

$= 2y^2+14xy$

$= y (2y+14x)$