Question

Phân tích đa thức thành nhân tử:

\(a,x^2-3x+xy-3y\)

\(b,x^2-2xy+y^2-4\)

\(c,x^2+x-y^2+y\)

Answer 1

a)\(x^2-3x+xy-3y=x\left(x+y\right)-3\left(x+y\right)=\left(x-3\right)\left(x+y\right)\)

b)\(x^2-2xy+y^2-4=\left(x-y\right)^2-2^2=\left(x-y+2\right)\left(x-y-2\right)\)

c)\(x^2+x-y^2+y=\left(x+y\right)\left(x-y\right)+\left(x+y\right)=\left(x+y\right)\left(x-y+1\right)\)