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