已知x+2y=3,x^2-4y^2=-15,求x-2y的值 已知x+2y=3,x^2-4y^2=-15.(1)求x-2y
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
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4x=9y求(1)x+y/y (2)y-x/2x
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*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=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知4x-2y=0,求x-y/3x+2y的值
已知x/y=3/4,求2x-y/x+y的值.
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
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.