caiet studentesc = s
caiet de matematica = m
carnet vocabular = v
3s + 2m + 2v = 26 - relatia 1
2s + 4m + v = 25 - relatia 2
4s + 2m + 3v = 33 - relatia 3
scadem relatia 3 si 1
==> s+v=7
scadem relatia 1 si 2
==> s-2m+v=1
dar noi stim s+v, deci inlocuim
7-2m=1
2m=6
m=3
adunam relatiile 1 si 2, iar dupa scadem relatia 3
5s+6m+3v=51
==>s+4m=18
s+4 ori 3=18
s+12=18
s=6
v=7-6=1