已知xy-x-y=11,求(xy-1)^2+(x+y-2)(x+y-2xy)的值.

已知xy-x-y=11,求(xy-1)^2+(x+y-2)(x+y-2xy)的值. 已知XY为正数,X+Y=1 求1/XY+XY的最小值 已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y) 已知x=y=11,求(xy-1)的平方+（x+y-2)乘以(x+y-2xy) 已知x-y=11求(xy-1)的平方＋(x+y-2)×(x+y-2xy)的值 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 已知x y=1,xy=-3,求2xy-4x 4(y-2(xy-x)) .已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 已知x^2+y^2=7,xy=-1,求代数式：5x^2-(3xy+4y^2)-(11xy-2y^2)-7x^2 已知x^2+y^2=7,xy=-1,求代数式:5x^2-3xy-4y^2-11xy+2y^2-7x^2 已知|x+y+1|+|xy+3|=0,求代数式xy^3+X^3y 已知X、Y属于R+,且XY-(X+Y)=1,求XY的范围 已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y答案是1/x-1/y=2(y-x)/xy=2 得：x-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy)=xy/(-7xy)=-1/7 谁能帮我解释一下=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy) 是怎 已知x²-xy=14,xy-y²=-11,求x²-2xy+y²的值 已知x^2-xy=14,xy-y^2=-11,求x^2-2xy+y^2的值 已知x²+xy=2,xy+y²=1,求x²+2xy+y²的值 已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy 已知x-xy=8,xy-y=-9,求x+y-2xy的值