Question

Resolva
(x-y)^2 - (x+y)^2=-8

Answer 1

X^2-2XY+Y^2-X^2-2XY-Y^2=-8
-4XY=-8
XY=2

Answer 2

(x - y)^2 - (x + y)^2= - 8
x² - 2xy + y² - (x² + 2xy + y²) = - 8
x² - 2xy + y² - x² - 2xy - y² = - 8
x² - x² + y² - y² - 2xy - 2xy = - 8
- 4xy = - 8 (-1)
4xy = 8
xy = 8/4
xy = 2