Notam:
b = numarul baietilor
f = numarul fetelor
b = (b+f) ×2/3 - 12
f = 2b/3
b = (b+2b/3) × 2/3 - 12 |×3
3×b = 2×b+4×b/3 - 36
b = 4b/3 - 36 |×3
3b = 4b - 108
4b-3b = 108
b = 108 (baieti)
f = 2×108/3 = 2×36 = 72 (fete)
108 + 72 = 180 (elevi)
Metoda grafica:
2×b = 3×f
2×f - b = 36
b |____|____|____|
2×f |____|____|____|____|
4 segmente egale - 3 segmente egale = 1 segment egal = 36
b = 3×36 = 108 (baieti)
2×f = 4×36
2×f = 144
f = 144 : 2
f = 72 (fete)
