Răspuns :
Notez numarul cu a
(a : 7) x 3 = 12
a : 7 = 12 : 3
a : 7 = 4
a =4 x 7
a = 28 → numarul la care ma gandesc
Verific: ( 28 : 7 ) x 3 = 4 x 3 = 12
(a : 7) x 3 = 12
a : 7 = 12 : 3
a : 7 = 4
a =4 x 7
a = 28 → numarul la care ma gandesc
Verific: ( 28 : 7 ) x 3 = 4 x 3 = 12