I------I a=nr gaini
I------I------I------I------I------I------I 6a nr pui
I---------I a+5 gaini
I---------I---------I---------I---------I---------I 5(a+5)pui
5×5=25
25-5=20 gaini
20×6=120 pui
ecuatie
a=nr gaini
6a=nr pui
6a+5=5(a+5)
6a+5=5a+25
a=20 gaini
6a=120 pui