计算(-3x²y)²·(4xy-3x²y-2x³)
计算:(-7x²y)(2x²y-3xy³+xy)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
计算[xy(x²-3y)+3xy²]·(-2xy)+x³y²(2x-y)
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
计算(2x³-3x²y-2xy²)-(x³-2xy²+y³)
计算:x²y-(2xy²-5x²y)+3xy²-y³
计算:(-x)²x³·(-2y)³-(-2xy)²·(-3x)³y.
x·(9x³y-3xy²)÷(﹣3x²y) 计算
计算:x•(9x³y-3xy²)/(-3x²y)
计算:(xy-x²)×x-y/xy
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
计算x²y³-2x(4xy³)