Numerator x numerator
Denominator x denominator
9. 1/4 x 4/5
1 x 4 = 4
4 x 5 = 20
4/20 = 1/5
11. 7/10 x 4/21
7 x 4 = 28
10 x 21 = 210
28/210 = 14/105
12. 3/5 x 5/12
3 x 5 = 15
5 x 12 = 60
15/60 = 1/4
14. 9/11 x 4/15
9 x 4 = 36
11 x 15 = 165
36/165
15. 8/9 x 9/10
8 x 9 = 72
9 x 10 = 90
72/90 = 36/45
17. 3/4 x 2/8 x 2/3
3 x 2 = 6
4 x 8 = 32
6/32 = 3/16
3/16 x 2/3
3 x 2 = 6
16 x 3 = 48
6/48 = 1/8
18. 2/3 x 12/17
2 x 12 = 24
3 x 17 = 51
24/51 = 8/17
