`c, 7/2003 +(1/5 + 1996/2003)`
`= 7/2003 + 1/5 + 1996/2003`
`= (7/2003 +1996/2003)+1/5`
`= 2003/2003 +1/5`
`=1+1/5`
`=5/5+1/5`
`=6/5`
__
`d, (-15)/49 - (7/5 + 24/49)`
`= (-15)/49 - 7/5 - 24/49`
`= ( (-15)/49 - 24/49) - 7/5`
`= -39/49 - 7/5`
`=-538/245`
`->` Cậu có viết sai đề không vậy ạ ?