已知x+y=2,xy=1/2,求x³y+2x²y²+xy³

问题描述:

已知x+y=2,xy=1/2,求x³y+2x²y²+xy³

x³y+2x²y²+xy³
=xy(x²+2xy+y²)
=xy(x+y)²
=1/2(2)²
=2