已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?

已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x²+4x+y²-2y+5=0,则x+y= 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x^2+4y^2-4x+4y+5=0,求(y^4-x^4)/(y-2x)(x+y)*2x-y 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 已知：4x = 5y,求(x+y) ：y 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) 已知4x=9y求(1)x+y/y (2)y-x/2x 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y