notam: c-nr creioane
p-nr pixuri
5c+2p=40000
10c+5p=95000
5c+2p=40000/×2
10c+4p=80000
10c+5p=95000
10c+4p=80000
-
p=95000-80000
p=15000 lei
5c+2p=40000
5c+2×15000=40000
5c+30000=40000
5c=10000
c=10000:5
c=2000 lei
deci un creion costa 2000 lei,iar un pix costa 15000 lei