13-9 = 4
11-7 = 4
12-8 = 4
SPER CA TE - AM AJUTAT ! -_-
a-9=4
a=4+9
a=13
13-9=4
___________
a-7=4
a=4+7
a=11
11-7=4
_____________
a-8=4
a=4+8
a=12
12-8=4
