Question

Un pix si un stilou costa 5 lei,un stilou costa 7 lei,iar un pix si un caiet costa 6 lei .\Afla cat costa fiecare obiect repede
Coroana

Answer 1

$p+s=5 \\ s+c=7 \\ p+c=6 \\ p+s+s+c+p+c=5+7+6 \\ 2(p+s+c)=18 \\ p+c+s=18:2=9 \\ 6+s=9=\ \textgreater \ s=9-6=\ \textgreater \ s=3.lei.stiloul \\ p+7=9=\ \textgreater \ p=9-7=\ \textgreater \ p=2.lei.pix\\ 5+c=9=\ \textgreater \ c=9-5=\ \textgreater \ c=4.lei.caietul$