2个初2分式算题

a-b-3ab=0
a-b=3ab
2a-2b=6ab
a-b-6ab/2a-2b+3ab
=(3ab-6ab)/(6ab+3ab)
=-1/3
2.x/2=y/3=z/4=k
则
x=2k
y=3k
z=4k
3x+2y-z/x+2y+z=(6k+6k-4k)/(2k+6k-16k)
=-1

1
a-b-3ab=0
所以
a-b=3ab
则
a-b-6ab/2a-2b+3ab=3ab-6ab/6ab+3ab=1/3

2
x/2=y/3=z/4
设x=2m y=3m z=4m
则3x+2y-z/x+2y+z=6m+6m-4m/2m+6m+4m=2/3

1:-1/3
2:3/4
过程：1：a-b＝3ab，然后将a-b代入分式化简可的
2:设x/2=y/3=z/4＝a，然后将X,Y,Z化成a，代入化简可的