已知方程3(X-Y)^2-5X-2=2X-7Y-4.求X-Y的值
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知方程2X-3Y=-7 求3(X+Y)-6(X-Y)的值
已知x-y=3,求代数式7-x+y-(y-x)^2的值.
已知3x-2y/x+y=5/3求x;y的值
已知x,y,z,同时满足方程x+3y-5z=0,2x-y-3z=0求x:y:z的值
1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值
已知x-2y=2016,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x的值
已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值
已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值.
已知X/Y=5/3,求X/(X+Y)+X/(X-Y)-Y*2/(X*2-Y*2)的值.
不解方程2x+y=5;x-3y=1,求7y(x-3y)²-2(3y-x)³的值.
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y