5.
`(3 1/2+0,25)-(1/4-3,25+1/2)`
`=(7/2+1/4)-(1/4-13/4+1/2)`
`=(14/4+1/4)-(1/4-13/4+2/4)`
`=15/4-(-10/4)`
`=15/4+10/4`
`=25/4`
6.
`(2 + 1/2 + 2/3 - 3/4) - (3 + 1/4 - 1/2 - 4/3)`
`=2 + 1/2 + 2/3 - 3/4 - 3 - 1/4 + 1/2 + 4/3`
`=(2-3) + (1/2+1/2) + (2/3+4/3) + (- 3/4 - 1/4) `
`=-1 + 1 + 2 + (- 1) `
`=1`
7.
` -(11/14 - 8/19) + (3/14 - 8/19) `
` =-11/14 + 8/19 + 3/14 - 8/19 `
` =(-11/14 + 3/14 )+(8/19- 8/19) `
` =(-8)/14 +0 `
` =(-4)/7`
8.
` (2/3 + 3/4 - 4/5) + (5/6 - 7/8 + 9/10) + (1/2 + 1/8 - 1/10)`
` =(2/3 +1/2+5/6) +(3/4 - 4/5 ) +(1/8- 7/8 )+ (9/10 - 1/10)`
` =(4/6 +3/6+5/6) +(3/4 - 4/5 ) +(1/8- 7/8 )+ (9/10 - 1/10)`
` =2 +3/4 - 4/5 + (-3/4 )+ 4/5`
` =2 +(3/4 -3/4)+(4/5- 4/5)`
` =2 +0+0`
`=2`