Answer:
Ted is 6 years old
Leon is 7 years old
Andrew is 8 years old
Explanation:
Ted+Leon=13 ⇒T+L=13 ⇒L=13-T
Leon+Andrew=15 ⇒L+A=15 ⇒A=15-L ⇒A=15-(13-T) because Leon =13-Ted
A=2+T
Ted+Andrew=14
T+A=14 ( substitute Andrew age from A=2+T)
T+2+T=14
2T=12
T=12/2=6 (Ted is 6 years old)
A=2+T=2+6=8 ( Andrew is 8 years old)
Leon=13-T=13-6=7 ( Leons is seven years old)
check: Ted+Leon=13 ⇒ 6+7=13
Leon + Andrew=15 ⇒7+8=15
Andrew+Ted=14 ⇒ 6+8=14