计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
(xy-x²)²÷(x-y)²/xy·x-y/x² 计算
计算(1)3x/8y×16y²/27x² (2)(2xy-x²)÷x-2y/xy 2x-6
计算:(xy-x²)乘 x-y分之xy
计算:(xy-x²)×x-y/xy
计算 (x²+2xy+y²)(x²-xy+y²)²
计算18(4x²-xy)-19(4x²-xy)+(4x²-xy-1),
计算:(-7x²y)(2x²y-3xy³+xy)
计算(3x^3y-x^2y+1/2xy)÷(-1/2xy)
计算[5xy²(x²-3xy)-(-3x²y²)³]÷(-5xy)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
x-y/x²÷x²-2xy+y²/xy*(xy-x²)