Question

phân tích đa thức thành nhân tử 

a) x²-4x           b) x(x+y)-3x-3y        c) x²-2x+1-y²

2x³-8x                   b) x(x+y)-5x-5y               d) x²-y²-2y-1

Answer 1

`a)x^2-4x=x(x-4)`

`b)x(x+y)-3x-3y=x(x+y)-3(x+y)=(x+y)(x-3)`

`c)x^2-2x+1-y^2=(x-1)^2-y^2=(x-1-y)(x-1+y)`

`2x^3-8x=2x(x^2-4)=2x(x-2)(x+2)`

`b)x(x+y)-5x-5y=x(x+y)-5(x+y)=(x+y)(x-5)`

`d)x^2-y^2-2y-1=x^2-(y+1)^2=(x-y-1)(x+y+1)`

Answer 2