求2x+5y=12 3x-4y=-5
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.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值
求5x-2y=x-y=4x-3y-2的解
方程式计算5X-2=Y 4X+3=Y 求X.Y
若2x-3y=0,求5x+4y/3x-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.
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27