已知x-2y=3,则4y-2x+5=?

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x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知x-2y/2x+3y=3/4,则x：y= 已知x²+4x+y²-2y+5=0,则x+y= 已知4x=5y,那么(3x+y)/(x-2y)= 已知y/x=2,则求代数式x+y/4x-5y的值 已知x,y>0 2x+y+3=xy 求5x+4y最小值 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y