Răspuns :
Fie X numarul
X - X:4 = 27 |×4
4×X- X = 108
3×X = 108
X = 36
verificare:
36-36:4 =27
36-9 = 27
27 = 27
X - X:4 = 27 |×4
4×X- X = 108
3×X = 108
X = 36
verificare:
36-36:4 =27
36-9 = 27
27 = 27