1. 16.7 - ( - 8.9 ) = 16.7 + 8.9 = 25.6
2. 7.2 - 8.9 = - 1.7
3. 0 - 5.7 = - 5.7
4. - 13.6 - 14.4 = - 28
5. - 14.8 - ( - 8.12 ) = - 14.8 + 8.12 = - 6.68
6. 0 - ( - 19.3 ) = 0 + 19.3 = 19.3
7. - 7/24 - ( - 17/36 ) = - 7/24 + 17/36 = -21/72 + 34/72 = 13/72
8. 2/9 - 1/3 = 2/9 - 3/9 = - 1/9
9. 3 1/5 - ( - 4 1/7 ) = 16/5 + 29/7 =112 /35 + 145/35 = 257/35 = 7 12/34 = 7 6/17