已知xy²=-6,求-xy(x³y∧7-3x²y∧5-5y))如题

问题描述:

已知xy²=-6,求-xy(x³y∧7-3x²y∧5-5y))
如题

=-x^4y^8+3x^3y^6+5xy^2
=-(xy²)^4+3(xy²)^3+5(xy²)
=-1296-648-30
=-1974