Giúp em dk ah lm ơn đó ah thank you ah

` a, 3/5+(-4/3)+(-3/4)`

`= 3/5-4/3-3/4`

`=36/60-80/60-45/60`

`= -89/60`

`b, (-7/2)+(-2/3)+(-3/5)`

`= -7/2-2/3-3/5`

`=-105/30-20/30-18/30`

`= 143/30`

`c, (17/18:51/36)xx3/5`

`=2/3 xx 3/5`

`= 2/5`

`d, 7/15 xx [(-3)/8-3/7]`

`= 7/15 xx (-45)/56`

`=-3/8`