x³y-2x²y²+xy³

x³y-2x²y²+xy³

x³y-2x²y²+xy³
=xy(x²-2xy+y²)
=xy(x-y)²

原式=xy(x^2-2xy+y^2)=xy(x-y)^2

x³y-2x²y²+xy³
=xy(x²-2xy+y²)
=xy(x-y)²

x³y-2x²y²+xy³=xy(x²-2xy+y²)
=xy(x-y)²

=xy（x²-2xy-y²）=xy(x-y)²

xy(x2-2xy+y2)=xy（x-y)2, x2和y2是平方的意思