Răspuns :
Notez numarul cu a
a - 7 × 7 = ( 2 × 7 ) × ( 7 × 7)
a - 49 = 14 × 49
a - 49 = 686
a = 686 + 49
a = 735 → numarul
a - 7 × 7 = ( 2 × 7 ) × ( 7 × 7)
a - 49 = 14 × 49
a - 49 = 686
a = 686 + 49
a = 735 → numarul