已知{2X-3Y=11,X+4Y=5,则3X+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/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
(3x-2y)(4x-5y)-11(x+y)(x-y)+5xy,已知X=3又1/2,y=2又1/3
已知x-2y/2x+3y=3/4,则x:y=
已知4x=5y,那么(3x+y)/(x-2y)=
已知x,y>0 2x+y+3=xy 求5x+4y最小值
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.