Question

Phân tích thành nhân tử :

a) \(x^2-x-y^2-y\)

b) \(x^2-2xy+y^2-z^2\)

Answer 1

a, Ta có x² - x - y² - y

= ( x² - y² ) - ( x + y )

= ( x - y ).( x + y ) - ( x + y )

= ( x+ y ).( x - y -1 )

b, Ta có x² - 2xy + y² - z²

= ( x² - 2xy + y² ) - z²

= ( x - y )² - z²

= ( x - y - z ).( x - y + z )

Answer 2

a) x² - x - y² - y = x² - y² - x - y

=(x - y) (x + y) - (x + y)

=(x + y) (x - y - 1)

b) x² - 2xy + y² - z² = (x - y)² - z²

=(x - y- z) (x - y + z)