已知5x=4y,则x:y=():()

已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知：4x = 5y,求(x+y) ：y 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) 已知x²+4x+y²-2y+5=0,则x+y= 已知y/x=2,则求代数式x+y/4x-5y的值 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-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3X=5Y,则X:Y= 已知5x=7y,则x:y=( ) 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