已知3^x=2,2^x=1,3^y=4,2^y=5,求12^(3x-y)的值
已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-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3x-4y/2x+y=1/2 求x/y的值
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
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X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知3x-2y/x+y=5/3求x;y的值
已知4x-2y=0,求x-y/3x+2y的值
已知|2x-3y|+|3x-y-1|=0,求x,y的值.
已知x/y=3/4,求2x-y/x+y的值.
已知x^2=12,y^2=3,且|x-y|=y-x,求x+y的值.