若x+2y=2则3x*9y=
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若2x+3y=2004,则代数式2(3x-2y)-(x-y)+(-x+9y)=...
若2x+y=2012,则代数式2(3x-2y)-(x-y)+(-x+9y)=
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
若全集I={(x,y)|x,y∈R},集合M={(x,y)|(y-3)/(x-2)},N{(x,y)|y=x=1},则(
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
若3x-4y=0,则x/y=______,(x-y)/y=______,(3x+2y)/(2x+3y)=_____.
若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y=
若5x+3y=3x+4y=x+2y+6,则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)
已知x-2y=3,则(2x+y-6)/(3x-y-9)=?