计算:3xy(x²y-xy²+xy)-xy²(2x-xy+2x)

问题描述:

计算:3xy(x²y-xy²+xy)-xy²(2x-xy+2x)

原式=3x³y²-3x²y³+3x²y²-2x²y²+x²y³-2x²y²
=3x³y²-2x²y³-x²y²