Răspuns :
[tex]a+b=906 \\\\\\ (a-b):b=5 \ rest \ 31 \\\\ a-b=5b+31 \\\\ a=5b+31+b \\\\\\ a=6b+31 \\\\\\ 6b+31+b=906 \\\\ 7b=906-31 \\\\ 7b=875 \ \ \ |:7 \\\\ \boxed{b=125} \\\\\\ a=6*125+31 \\\\ a=750+31 \\\\ \boxed{a=781}[/tex]
daca a>b atunci, a+b=906 si (a-b) : b = 5 (rest 31) ↔ a - b = 5b+31 ↔ a=6b+31
              ↓
            6b+31  +  b = 906
             7b = 875
              b = 125  →  a = 6*125+31 = 781
                        a = 781
              ↓
            6b+31  +  b = 906
             7b = 875
              b = 125  →  a = 6*125+31 = 781
                        a = 781