Question

cate numere naturale impartite la 7 dau catul 5 ? Calculeaza suma acestora.

Answer 1

x:7=5 rest y. y<7
=>x=7•5 +y. => x=35+0=35
x=35+1=36
x=35+2=37
x=38
x=39
x=40
x=35+6=41
35+36+37+38+39+40+41=221