当2x-y\x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的値._数学解答

当2x-y\x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的値.

人气：230 ℃　时间：2020-03-20 13:07:41

解答

2x-y\x+y=3
2x-y=3(x+y)
2x-y=3x+3y
3x-2x=-y-3y
x=-4y

2x-y/2x+2y+x+y/6x-3y
=(-8y-y)/(-8y+2y)+(-4y+y)/(-24y-3y)
=3/2+1/9
=29/18