x+y=3xy
原式=[3(x+y)-4xy]分之[(x+y)+2xy]
=[3(3xy)-4xy]分之[(3xy)+2xy]
=5xy分之5xy
=1
x分之一加y分之一=3,求3x-4xy加3y分之x+2xy+y
x+y=3xy 原式=[3(x+y)-4xy]分之[(x+y)+2xy]=[3(3xy)-4xy]分之[(3xy)+2xy]=5xy分之5xy =1
1.已知x分之一+Y分之一=3,求x+2xy+y分之3x-4xy+3y的值
(x+y)\/xy=3 x+y=3xy x+2xy+y=5xy 3x-4xy+3y=5xy 所以值是1
已知,x分之一加y分之一等于3,求x加2xy加y分之3x减4xy加3y的值。还有一...
xy=3(x+y)(3x-4xy+3y)\/(x+2xy+y)=[3(x+y)-4xy]\/(x+y+2xy)=[3(x+y)-12(x+y)]\/[x+y+6(x+y)]=-9\/7 第二题不太清楚 2\/(x+3)+2\/(3-x)=-12\/(x^2-9)
已知X分之一加Y分之一等于三,求X+2XY+Y分之3X-4XY+3Y的值
由1\/X+1\/Y=3 可得y\/xy+x\/xy=3 x+y=3xy （X+2XY+Y）分之(3X-4XY+3Y) =（3x-4xy+3y）\/（x+2xy+y） =【3（x+y）-4xy】\/【（x+y）+2xy】 =（3×3xy-4xy）\/（3xy+2xy） =（9xy-4xy）\/5xy =5xy\/5xy =1...
(1)已知1\/x+1\/x=3,求3x-4xy+3y\/x+2xy+y的值 (2)已知x为整数,且2\/x+3...
解：（1）∵1\/x+1\/y=3 ∴(y+x)\/xy=3 ∴x+y=3xy (3X-4XY+3y)\/(X+2XY+Y)=[3(x+y)-4xy]\/[(x+y)+2xy]=(9xy-4xy)\/(3xy+2xy)=5\/5 =1 （2）2\/x+3+2\/3-x+2x+18\/x^2-9 =[2(X-3)-2(X+3)+2X+18]\/(X+3)(X-3)=2(X+3)\/(X+3)(X-3)=2\/(X-3)...
已知1\/x+1\/y=3,求(3x-5xy+3y)\/(x-2xy+y)
1\/x+1\/y=3 去分母得 x+y=3xy (3x-5xy+3y)\/(x-2xy+y)=[3(x+y)-5xy]\/(x+y-2xy)=(9xy-5xy)\/(3xy-2xy)=4xy\/xy=4
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1\/x-1\/y=3,求(3x+4xy-3y)\/(x-2xy-y)的值
1\/x-1\/y通分=(y-x)\/xy=3 y-x=3xy x-y=-3xy 所以原式=[3(x-y)+4xy]\/[(x-y)-2xy]=[3(-3xy)+4xy]\/[(-3xy)-2xy]=-5xy\/(-5xy)=1
...万分之一等于五则代数式x减2xy加y分之3x加4xy加3y的值为
x=49999分之一万
已知1\/x-1\/y=3,求3x-5xy-3y\/x-2xy-y的值.
声明楼主所求式子很可能表述不正确，如是（3x-5xy-3y)\/(x-2xy-y），解法如下。由已知x≠0，y≠0，故等式左右同乘以xy得 y-x=3xy 所求式子化为：原式=[3(x-y)-5xy]\/[(x-y)-xy]=[(-9xy)-5xy]\/[(-3xy)-xy]=14xy\/4xy=7\/2 ...
