tatal=t
fiul mare=x
fiul mijlociu=y
fiul mic=z
t=1+3x
x=y+z
y=z+1
7+x+7+y+7+z=t+7
21+x+y+z=7+t
21-7+x+y+z=t
14+x+y+z=t
14+(y+z)+(z+1)+z=1+3x
14+z+1+z+z+1=1+3*(z+1+z)
16+3z=1+3z+3+3z
16+3z=4+6z
6z=16-4+3z
6z=12+3z
6z-3z=12
3z=12
z=12:3
z=4 ani
y=4+1
y=5 ani
x=4+5
x=9 ani
t=1+3*9
t=28 ani