已知x-xy=10,xy-y=2,则x-y=（ ）,-2xy+x+y=（ ）.

已知x-xy=10,xy-y=2,则x-y=（ ）,-2xy+x+y=（ ）. 已知x-xy=20,xy-y=-10,则x-y=( ),x+y-2xy=( ). 已知x-xy=20,xy-y=-10,则x-y=?,x+y-2xy? 已知x+y=1,xy=-2,则x²y+xy²-2xy 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=（ ）. 已知:x-xy=20,xy-y=12,则x-y=...,-2xy+x+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xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-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=8,xy-y=-9,求x+y-2xy的值 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? 已知x-y=3,xy=10,则x²y-xy²= 已知x+y=5,xy=2则x^2y+xy^2=( ) 已知x+y=1,xy=1/5,则x^2y=xy^2 已知x+y=6,xy=-3,则x^2y+xy^2=?