1 )
` -3 1/2 - 2 1/4 = -3,5-2,25= -(3,5+2,25)=-5,75`
2
`-2/21 + 2 3/14 = -2/21 + 2 + 3/14 `
` = 2 +` \(\dfrac{-4+9}{42}\)
` = 2 + 5/42`
` = 2 5/42`
3 )
`-2/33 + 5/55=-2/33 +1/11 =` \(\dfrac{-2+3}{33}\) = ` 1/33`
4) `-3/23 +2 4/69 =-3/23 +2 +1/69 `
` = 2 - 3/23 + 4/69`
` = 2- 9/69 +4/69`
` =2/1 - 5/69 `
` = 1 69/69 - 5/69 `
` = 164/69`
5 ) ` -7/2 + 3/4 - 17/12`
=\(\dfrac{-42+9-17}{12}\)
`=-50/12 = -25/6`
6) `-1/12 - (2 5/8 -1/3 )`
`= 1/12 - 2 5/8 + 1/3`
`=1/12-5/8+1/3-2`
`=`\(\dfrac{-2-15+8}{24}-2\)
`=-9/24-2`
`=-3/8 -2`
`= 2 3/8`