Question

Phân tích đa thức thành nhân tử:  
a) 3x-3y-x²+2xy-y²
b) x²-4x²y²+y²+2xy
c) (x+y)³-(x-y)³
d) x²-5x-14

Answer 1

a) 3(x-y) - (x-y)^2

 =(x-y)(3-x+y)

Answer 2

b) =(x+y)^2 - (2xy)^2

= (x+y-2xy)(x+y+2xy)

Answer 3

\(a,=3\left(x-y\right)-\left(x-y\right)^2=\left(x-y\right)\left(3-x+y\right)\\ b,=\left(x+y\right)^2-4x^2y^2=\left(x-2xy+y\right)\left(x+2xy+y\right)\\ c,=\left(x+y-x+y\right)\left[\left(x+y\right)^2+\left(x+y\right)\left(x-y\right)+\left(x-y\right)^2\right]\\ =2y\left(x^2+2xy+y^2+x^2-y^2+x^2-2xy+y^2\right)\\ =2y\left(3x^2+y^2\right)\\ d,=x^2+2x-7x-14=\left(x+2\right)\left(x-7\right)\)

Answer 4

d) = x(x-7) + 2(x-7)

= (x+2)(x-7)