x^2+y^2-x-6y+9.25=0,求x,y的值

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? x^2+y^2-x-6y+9.25=0,求x,y的值 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 已知x^2+y^2+13-4x+6y=0,求(2x-y)^2-2(2x-y)(x+2y)+(x+2y)^2 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的值 {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 x^2+4y^2-6x+4y+10=0,求x^4-y^4/(x+2y)(x-2y)*x+2y/xy^2+y^3除以（x^2+y^2/y)^2的值 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 (X,Y) f(x,y)={12y^2,0 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y [(2x-y)(2x+y)+y(y-6x)]÷2x=? （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 x*x+2x+y*y-4y+5=0 x= y= 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y