已知x/y=2013,则x+y/x-2012y=
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
1.已知1/x+1/y=-1/x+y,则y/x+x/y=?
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
已知实数x,y满足|x|+x+y=10、x+|y|-y=12,则x+y的值?
已知x、y满足方程组3x+y=2013,x+3y=2012,求x-y
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)
数学题已知p=x^/x-y-y^/x-y,q=(x+y)^-2Y(X+Y),
已知:4x = 5y,求(x+y) :y
已知3X=5Y,则X:Y=
已知:3x=7y,则x:y=------------------