Sagot :
x - Jim
y - Carla
z - Tomy
[tex]y=x+5\\ z=y+6\\ x+y+z=31\\\\ x=y-5\\ z=y+6\\ x+y+z=31\\\\ y-5+y+y+6=31\\ 3y=30\\ y=10\\\\ x=10-5\\ x=5\\\\ z=10+6\\ z=16 [/tex]
y - Carla
z - Tomy
[tex]y=x+5\\ z=y+6\\ x+y+z=31\\\\ x=y-5\\ z=y+6\\ x+y+z=31\\\\ y-5+y+y+6=31\\ 3y=30\\ y=10\\\\ x=10-5\\ x=5\\\\ z=10+6\\ z=16 [/tex]
let the age of jim be x
carla's age= x+5
tomy's age= 6+5+x
sum of their ages=31
x+x+5+x+5+6=3x+16=31
3x=31-16
=15
x=15 divided by 3
= 5
jim's age=5
carla's age=10
tomy's age = 16
carla's age= x+5
tomy's age= 6+5+x
sum of their ages=31
x+x+5+x+5+6=3x+16=31
3x=31-16
=15
x=15 divided by 3
= 5
jim's age=5
carla's age=10
tomy's age = 16