Question

Daca elevii unei clase ar fi asezati cate 2 in banca, ar mai fi necesare 5 banci, iar, daca ar fi asezati cate 3 in banca, ar ramane 3 banci libere. Cati elevi si cate banci sunt in clasa?

Answer 1

$x\to nr. \ de \ banci \\\\ 2(x+5)\to nr. \ de \ copii \\ 3(x-3)\to nr. \ de \ copii \\\\\\ 2(x+5)=3(x-3) \\\\ 2x+10=3x-9 \\\\ 2x-3x=-9-10 \\\\ -x=-19 \\\\ \boxed{x=19 \ banci} \\\\\\ 3(19-3)=3*16 \to \boxed{48 \ copii}$