`b) 1/2 + 3/4 - ( 3/4 - 4/5)`
`= 1/2 + 3/4 - 3/4 + 4/5`
`= 1/2 + ( 3/4 - 3/4) + 4/5`
`= ( 1/2 + 4/5) + 0`
`= 13/10 + 0`
`= 13/10`
`d) 2/5 . 1/3 - 2/15 : 1/5 + 3/5 . 1/3`
`=2/5 . 1/3 - 2/15 . 5 + 3/5 . 1/3`
`= 2/5 , 1/3 - 2 . 1/3 + 3/5 . 1/3`
`= 1/3 . ( 2/5 - 2 + 3/5)`
`= 1/3 . (-1)`
`= -1/3`
`e) 9/27 + 8/24 + 18/27 - \frac{-16}{24} + 2/3`
`= ( 9/27 + 18/27) + ( 8/24 + 16/24) + 2/3`
`=1 + 1 + 2/3`
`= 2 + 2/3`
`= 8/3`
