t = m + f - 5
f + 7 = (m + 7) : 3
3×f + 21 = m + 7 ==> m = 3×f + 14
m + t + f + 3×7 = 108
m + t + f = 108 - 21 = 87
f |____|
m |____|____|____|+14
t |____|____|____|____|+9
87 - (14+9) = 87 - 23 = 64
64 : 8 = 8 (un segment egal)
f = 8 ani (fiul)
m = 3×8+14 = 24+14 = 38 ani (mama)
t = 4×8+9 = 32+9 = 41 ani (tatal)