x-y=2,则x^2-2xy+y^2

x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 函数f(xy,x+y)=x^2+xy+y^2,则df(x,y)=? f(xy,x-y)=x^2+3xy+y^2,则f(x,y)=? 已知x+y=1,xy=-2,则x²y+xy²-2xy (-x-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) （x^2+xy/x-y)/（xy/x-y)计算 f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y 已知x-y=3xy,则2x+3xy-2y除以x-2xy-y=? 已知x+xy+y=3,则(3x+2xy+3y)/(2x+xy+2y)= 已知x-y=3xy,则2x+3xy-2y/x-2xy-y= 已知x.y满足X2-y2=2xy.则x-y/x+y=?x. 已知x-xy=10,xy-y=2,则x-y=（ ）,-2xy+x+y=（ ）. 已知xy/x+y=3,则代数式2x-7xy+2y/-x+xy-y的值是多少? 已知x-xy=20,xy-y=-10,则x-y=( ),x+y-2xy=( ). 已知x-xy=20,xy-y=12,则x-y= ,-2xy+x+y= 已知x-xy=20 xy-y=12,则x-y=（ ）,x+y-2xy=（ ）.