Ajutooooorrrrrtrrrrrrr

Răspuns:
1. 4 grupe
a)20-5-5-5-5=0
b)20:5=4
2.15-3-3-3-3-3=0
15:3=5
3.18:2=9
18:3=6
18:6=3
4.49:7=7
54:9=6
64:8=8