(-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)]
问题描述：
(-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)]
答
原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)=(x²y²/9)xy²=(x³y^4)/9即x的三次方乘y的四次方除以9