Răspuns :
Fie a numarul
[(a : 5 ) × 2 ] : 4 + 5 = 9
[(a : 5 ) × 2 ] : 4 = 9 - 5
[(a : 5 ) × 2 ] : 4 = 4
(a : 5 ) × 2 = 4 × 4
(a : 5) × 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 × 5
a = 40 (numarul)
Verificare:
(40 : 5)×2 :4 + 5 = 9
8 × 2 : 4 + 5 = 9
16 : 4 + 5 = 9
4 + 5 = 9
9 = 9
[(a : 5 ) × 2 ] : 4 + 5 = 9
[(a : 5 ) × 2 ] : 4 = 9 - 5
[(a : 5 ) × 2 ] : 4 = 4
(a : 5 ) × 2 = 4 × 4
(a : 5) × 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 × 5
a = 40 (numarul)
Verificare:
(40 : 5)×2 :4 + 5 = 9
8 × 2 : 4 + 5 = 9
16 : 4 + 5 = 9
4 + 5 = 9
9 = 9