已知x+y=2,xy=12
已知x²-7xy+12y²=0求x²-xy+y²/2xy的值
已知:xy+x=-1,xy-y=-2.
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x-y=4xy,则2x+3xy-2yx-2xy-y
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=2,xy=12
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
已知x+y=12,xy=9,求(x+3xy+y)/(xy+xy)的值
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=