Question

La impartirea unui nr nat n la 13 obtine restul de doua ori mai mare decat catul . Care este nr n

Answer 1

n : 13 = c (rest 2*c)

        ↓

  n = 13*c + 2*c = 15c

inseamna ca n={0*15=0; 1*15=15; 2*15=30; 3*15=45; s.a.m.d. }

Verificare: n=0     ⇒ 0:13=0 (rest 2*0=0)

                 n=15 ⇒ 15:13=1 (rest 2)

                 n=30 ⇒ 30:13=2 (rest 4)

                                etc.                            (Adevarat)