`e) -1 2/3 + 3/4 - 1/2 + 2 1/6`
`= -5/3 + 3/4 - 1/2 + 13/6`
`= -20/12 + 9/12 - 6/12 + 26/12`
`= (-20 + 9 - 6 + 26)/12`
`=9/12`
`= 3/4`
``
`f) -1 + 1/3 - 1/9 + 1/27 - 1/81`
`= -81/81 + 27/81 - 9/81 + 3/81 - 1/81`
`= (-81 + 27 - 9 + 3 - 1)/81`
`= -61/81`
``
`g) 7/12 - ( -1/5) - 5/6 + 2/3 + (-1/5)`
`= 7/12 + 1/5 - 5/6 + 2/3 - 1/5`
`= ( 7/12 - 5/6 + 2/3) + ( 1/5 - 1/5)`
`= ( 7/12 - 10/12 + 8/12) + 0`
`= 5/12 + 0`
`= 5/12`
``
`h) 1/2 + ( 16/21 + 27/13) - ( 14/13 - 5/21)`
`= 1/2 + 16/21 + 27/13 - 14/13 + 5/21`
`= 1/2 + ( 16/21 + 5/21) + ( 27/13 - 14/13)`
`= 1/2 + 1 + 1`
`= 1/2 + 2`
`= 1/2 + 4/2`
`= 5/2`
