t-varsta tatei
m-varsta mamei
x-varsta unui fiu
y-varsta celuilalt fiu
|..............t.................|
|.......x+y.......||...10...|
|..........m...........||..4..|
|.....x.....|
|..y..||.2.|
t+m+x+y=100
t+t-4+t-10=100
3t -14=100
3t=100+14
3t=114
t=114:3=38
m=38-4=34
x+y=38-10
x+y=28
y+2=x
y+2+y=28
2y+2=28
2y=28-2
2y=26
y=26:2=13
x=13+2=15