已知(3x+2y-20)^2+/4x-5y-19/=0,则x=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(3x+2y-20)^2+/4x-5y-19/=0,则x=y= 已知x²+4x+y²-2y+5=0,则x+y= 已知x,y>0 2x+y+3=xy 求5x+4y最小值 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X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/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3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)} 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0