Question

Va rog raspundeti urgent la urmatoarea problema :
Daca elevii unei clase ar fi asezati cate 2 in banca ar ramane 3 banci libere, iar daca ar fi asezati cate 3 elevi in banca ar ramane 8 banci libere. Cati elevi si cate banci sunt in clasa?

Answer 1

$x\to nr. \ de \ banci \\\\\\ 2(x-3) \to nr. \ de \ elevi \\3(x-8) \to nr. de \ elevi \\\\ 2(x-3)=3(x-8) \\\\ 2x-6=3x-24 \\\\ 2x-3x=-24+6 \\\\ -x=-18 \\\\ \boxed{x=18 \ banci} \\\\ 2(x-3)= 2(18-3)= \\\\ =2*15= \\\\ =\boxed{30 \ elevi}$

Answer 2

a = nr de banci 
2xa-3x2=elevi 
3xa -8x3 =elevi 
2a-6=3a - 24
24-6=3a-2a
18=a
2x18 -3x2= 36-6=30 elevi 
3x18 - 3x8= 54-24=30 elevi                                 R: Sunt 18 banci si 30 de elevi