化简.很简单的.[(x^2-2xy)+x^2]/(y^2+2xy)-(x^2+2xy)
(xy-x^2)乘以(xy)/(x-y)
(x^2+xy/x-y)/(xy/x-y)计算
(x+y-2xy)(x+y-2)+(1-xy)²
(x^2-xy)y÷y-x/xy怎么做?
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
(-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)]
xy(xy+1)+(xy+3)-2(x+y+2分之一)-(x+y-1)的平方
已知x-xy=8,xy-y=-9,求x+y-2xy的值
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
x的平方-2xy/xy-2y的平方
计算3xy[2xy-x(y-2)+x-1]
计算:3xy[2xy-x(y-2)+x]