Question

(x-y+2) ² - (x - y -2) ²

Answer 1

(x-y+2) ² - (x - y -2) ²
x² + y² + 4 - x² + y² + 4
x² - x² + y² + y² + 4 + 4
2y² + 8
y² = 8/2
y² = 4
y = √4
y = 2 

Answer 2

(x-y+2) ² - (x - y -2) ²

(x-y+2).(x-y+2) - (x - y -2) ²

x²-xy+2x-xy+y²-2y+2x-2y+4- (x - y -2) ²

x²+y²+4x-4y-2xy+4-(x-y-2).(x - y -2)

x²+y²+4x-4y-2xy+4-(x²-xy-2x-xy+y²+2y-2x+2y+4)

x²+y²+4x-4y-2xy+4-x²+xy+2x+xy-y²-2y+2x-2y-4


x²-x²+y²-y²+4x-2x-2x-4y-2y-2y-2xy+xy+xy+4-4


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