若x^2+y^2+2x-2y+2=0则x+y=?

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若2x=3y,则(x*x+y*y)/x*x=? 若x+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 若x-y不等于0,2x-3y=0,则分式(10x-11y)/(x-y)的值是（）?(10x-11y)/(x-y) =[(8x-8y)+(2x-3y)]/(x-y) =8为什么8X-8Y=8？(10x-11y)/(x-y)=[(8x-8y)+(2x-3y)]/(x-y)=8+(2x-3y)]/(x-y)=8+0=8 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 化简y(x+y)+(x+y)(x-y)-x^2 若2x-5y=0,则y：x 因式分解x(x+y)(x-y)-x(x+y)^2 若x,y满足|x-y+1|+(x+y+3)^2=0则x^2-y^2= 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y= 若线段x ,y 满足[2x-3y]*[3x+2y]=0 则x/y=? 若x^2+y^2-6x+8y+25=0 则y/x-x/y的值是