Given Expression, 

`= 108 ÷ 9 + 2/5 xx 13/4`

`= 108/9 + 13/10`

`= (12 + 13/10)`

`= 133/10`

`= 13 3/10`.

Given Expression,

`1/2 ÷ 5/3 + 1/4 xx 3/5 - 2/5` of `5/7`

`= 1/3 ÷ 5/3 + 1/4 xx 3/5 - 2/7`

`= 1/3 xx 3/5 + 3/20 - 2/7`

`= 1/5 + 3/20 - 2/7`

`= (4 + 3)/20 - 2/7`

`= 7/20 - 2/7`

`= ((49 - 40)/(140))`

`= 9/140`.

Given Expression ,

`= 3.5 ÷ 4.9 + 0.5 xx 0.3 - 0.1`

`= 3.5/4.9 + 0.15 - 0.1`

`= 5/7 + 15/100 - 1/10`

` 5/7 + (15 - 10)/100`

`= 5/7 + 5/100`

`= 5/7 + 1/20`

`= ((100 + 7)/(140))`

`= 107/140`

`= 0.764`

Given Expression ,

` = 2 - [3 - { 6 - (5 - 1) } ]`

`= 2 - [3 - {6 - 4} ]`

`= [3 - 2]`

`= (2 - 1)`

`= 1`.

`[13/4 ÷ { 5/4 - 1/2 (5/2 - (3-2)/12)}]`

`= [13/4 ÷ { 5/4 - 1/2 (5/2 - 1/12)}]`

`= [ 13/4 ÷ { 5/4 - 1/2 ((30 - 1)/12)}]`

`= [ 13/4 ÷ { 5/4 - 29/24}]`

`= [ 13/4 ÷ { (30 - 29)/24}]`

`= [ 13/4 ÷ 1/24]`

`= [ 13 xx 24]`

`= 78`.