8. 2/7
2 2 4
---* ---- = -----
7 2 14
2 3 6
--- * ----- = -----
7 3 21
9. 6 /5
6 4 24
--- * ---- = -----
5 4 20
6 10 60
--- * ------- = ------
5 10 50
10. 9 / 12
9 9/3 3
---- = ------- = ----
12 12/3 4
9 5 45
--- * ----- = ------
12 5 60
11. 18 /16
18 18/2 9
--- = ------ = ------
16 16/2 8
18 3 54
---- * ----- = -----
16 3 48
