Răspuns :
(5s+6c)-(2s+3c)=36-15
3s+3c=21
(3s+3c)-(2s+3c)=21-15
1s=6 lei
6x2+3c=15
3c=15-12=3 lei
1c=3:3=1 leu costa creionul
6 lei costa stiloul
3s+3c=21
(3s+3c)-(2s+3c)=21-15
1s=6 lei
6x2+3c=15
3c=15-12=3 lei
1c=3:3=1 leu costa creionul
6 lei costa stiloul