2x^2-4xy+2y^2-3(x-y+3)因式分解

2x^2-4xy+2y^2-3(x-y+3)因式分解

2x^2-4xy+2y^2-3(x-y+3)
=2(x²;-2xy+y²;)-3(x-y)-9
=2(x-y)²;-3(x-y)-9
=[2(x-y)+3][(x-y)-3]