(8xy-x^2+y^2)-(x^2-y^2+8xy)

（xy-x^2)乘以(xy)/(x-y) 已知x-xy=8,xy-y=-9,求x+y-2xy的值 因式分解:8(x-2y)-x(7x+y)+xy. （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-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y) 已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值 （1） -3X^-2XY-8XY-(-5Y^2)-2X^2-Y^2 xy/3x+2y=1/8 xy/2x+3y=1/7 -4x²y-8xy²+2x²y-3xy² x-y/x²÷x²-2xy+y²/xy*（xy-x²）