1. .......................=6204/6695
1) 1 3/13+14/65=1 15/65+14/65=1 29/65
2) 21 - 18 6/13=21 - 18 - 6/13=3-6/13=2 7/13
3) 5 10/11 - 5 7/18=5 180/198 - 5 77/198=103/198
4) 1 29/65 : 2 7/13=94/65 * 13/33=94/165
5) 94/195 : 103/198=94/195 * 198/103=6204/6695
.
2. ....................=12 431/882
1) 6 2/11 - 5 1/77=6 14/77 - 5 1/77=1 13/77
2) 17/35+1 2/5=17/35+1 14/35=1 31/35
3) 1 13/77 * 1 31/35=90/77 * 66/35=108/49
4) 108/49 * 8 1/9=108/49 * 73/9=876/49=17 43/49
5) 17 43/49 - 5 7/18=17 774/882 - 5 343/882=12 431/882