Odpowiedź:
Szczegółowe wyjaśnienie:
=12/20+5/20=17/20
=5/5 -2/5=3/5
=1 9/9 -7/9=1 2/9
=4 7/7 -1 3/7=3 4/7
=13 9/6=14 3/6=14 1/2
=2
=7 3/4
=115 5/5=116
=18/21 -2/21=16/21
=4 1/12 -2/12=3 13/12 -2/12=3 11/12
=8 3/24- 2 16/24=7 27/24 -2 16/24=5 11/24
=11 3/9 -5 4/9=10 12/9 -5 4/9=5 8/9