Notam:
a = numarul de papusi
3×a = a : 2 + 25
3×a - a:2 = 25
3×a |___|___|___|___|___|___|
a:2 |___|
avem 6 segmente egale - 1 segment egal = 5 segmente egale = 25
25 : 5 = 5 (un segment egal)
3×a = 6×5 = 30
a: 2 = 5
a = 5×2 = 10
Verificare:
3×10 = 10 : 2 + 25
30 = 5+25
30= 30
Raspuns:
10 papusi