已知x-2y=0,则2x^2÷4y^2

已知x*x+4x+y*y-2y+5=0,则x*x+y*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x²+4x+y²-2y+5=0,则x+y= 已知4x=9y求(1)x+y/y (2)y-x/2x 已知X^2+Y^2+4X-6Y+13=0,X、Y为实数,则Y^2等于? 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,y为实数,根号3x+4 +y^2-6Y+9=0则x+y=? 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知x²+y²-6x+4y+13=0,则x的y次方的值?已知4x²+2y²-4x 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²