`1)`

`(7-1/5+1/3) -(6+9/5 +4/3)`

`=7-1/5+1/3 -6-9/5 -4/3`

`=(7-6)+(-1/5-9/5)+(1/3-4/3)`

`=1 -2 -1`

`=-2`

`2)`

`7+(7/12 -1/2 +3)-(1/12 +5)`

`=7+7/12 -1/2 +3-1/12 -5`

`=(7+3-5)+(7/12-1/12)-1/2`

`=5 +1/2-1/2`

`=5`

`3)`

`(3-1/4+2/3)-(5-1/3 -6/5) -(6-7/4 +3/2)`

`=3-1/4+2/3-5+1/3 +6/5 -6+7/4 -3/2`

`=(3-5-6)+(-1/4+7/4)+(2/3+1/3) +6/5-3/2`

`= -8 + 3/2 + 1 +6/5-3/2`

`=(-8+1)+(3/2-3/2)+6/5`

`=-7 +6/5`

`=-29/5`

`4)`

`(2/7 -9/4)-(-3/7 +5/4)-(2/4 -9/7)`

`=2/7 -9/4+3/7 -5/4-2/4 +9/7`

`=(2/7+3/7+9/7)+(-9/4-5/4-2/4)`

`=2 - 4`

`=-2`

`5)`

`6``2/5 -(2``4/9 +4``2/5)`

`=32/5 -(22/9 +22/5)`

`=32/5 -22/9 -22/5`

`=(32/5-22/5)-22/9`

`=2 -22/9`

`=-4/9`

`6)`

`(6``4/9 +3``7/11) - 4``4/9`

`=(58/9 + 40/11) - 40/9`

`=58/9 + 40/11 - 40/9`

`=(58/9- 40/9)+ 40/11`

`=2+ 40/11`

`=62/11`