Question

Simplifique: a) ( x-5)2 - ( x-5)2

Answer 1

a)
= (x - 5)² - ( x - 5)²

= x² - 2.5.x + 25 - (x² - 2.5.x + 25)

= x² - 10x + 25 - (x² - 10x + 25)

= x² - 10x + 25 - x² + 10x - 25

= 0

Resp.: 0

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b)
= (x + y)² - x² - y²

= x² + 2xy + y² - x² - y² 
= x² - x² + y² - y² + 2xy

= 2xy

c)

c)
= (2x + 2) - 4x.(x - y)
= 2x + 2 - 4x² + 4xy = - 4x² + 2x + 4xy + 2