Odpowiedź:
7. 8/12 = 2/3
6/9 = 2/3
5/15 = 1/3
4/16 = 1/4
8. 2/5+1/5= 3/5 3/7 + 6/7 = 9/7 = 1 2/7
3/7+6/7 = 9/7
3 4/9 + 1 3/9 = 30/9 + 12/9 = 42/9 = 4 6/9