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已知,1\/x+1\/y=3,求3x-2xy+3y\/x+5xy+y的值
原式=（3-2）\/(3+5)=1\/8
已知1\/x+1\/y=3,求分式3x-2xy+3y\/x+xy+y的值
1\/x+1\/y=3 x+y=3xy (3x-2xy+3y)\/(x+xy+y)=(3(x+y)-2xy)\/[(x+y)+xy]=(9xy-2xy)\/(3xy+xy)=7\/4
已知1\/x+1\/y=3 求3x+xy+3y\/x-xy=y的值
解：(3x+xy+3y)\/(x-xy+y) 上下同除以xy =(3\/y+1+3\/x） \/ (1\/y-1+1\/x)=[3(1\/x+1\/y)+1] \/ (1\/x+1\/y -1)=(3×3+1)\/(3-1)=10\/2 =5
2.已知1\/x+1\/y=3,则(3x+xy+3y)\/(x-xy+y)=( ).
因为 1\/x+1\/y=3,所以 x + y = 3xy,代入:（3x+xy+3y）\/(x-xy+y)=[3( x+y)+xy]\/(x+y-xy)=4xy\/(2xy)=2
已知x分之1+y分之1=3,求x+xy+y分之3x-2xy+3y的值
数理答疑团为您解答，希望对你有所帮助。1\/x +1\/y =3,(x+y)\/xy=3,x+y=3xy,(3x-2xy+3y)\/(x+xy+y)=(7xy)\/(4xy)=7\/4 祝你学习进步，更上一层楼！(*^__^*)
若1\/x+1\/y=3,则x\/3x+3y+y+2xy\/3x+3y=
1\/X+1\/Y=3,X+Y=3XY,∴X\/(3X+3Y)+(Y+2XY)\/(3X+3Y)=(X+Y+2XY)\/3(X+Y)=(3XY+2XY)\/9XY =5\/9.
已知1\/x-1\/y=3,求分式3x-xy+3y\/x+xy+y的值.
已知1\/x-1\/y=3,应该是1\/x+1\/y=3,[按原式得不出结果!]如此,则3xy＝x+y （3x-xy+3y）\/（x+xy+y）＝2
已知1\/X+1\/Y=3求X+2XY+Y\/2X-3XY+2Y.
1\/x +1\/y=3 (x+y)\/(xy)=3 x+y=3xy (x+2xy+y)\/(2x-3xy+2y)=[(x+y)+2xy]\/[2(x+y)-3xy]=(3xy+2xy)\/(2·3xy-3xy)=5xy\/(3xy)=5\/3
已知1\/x+1\/y=2 则分式3x-5xy+3y\/x+3xy+y=?
解：∵1\/x+1\/y=2 ∴x+y\/xy=2 x+y=2xy 3x-5xy+3y\/x+3xy+y =3(x+y)-5xy\/(x+y)+3xy =3×2xy-5xy\/2xy+3xy =xy\/5xy =1\/5
已知X分之一加Y分之一=2,求代数式x+xy+y分之3x-5xy+3y的值。
(3x-5xy+3y)\/(x+xy+y)分式上下同除xy，得，(3\/y-5+3\/x)\/(1\/y+1+1\/x)=1\/3
