Answer:
58 children's tickets were sold!
Explanation:
c=# of children's tickets sold
a=# of adults' tickets sold
6.5c+9.9a=1258.10
c+a=147
a=147-c
6.5c+9.9(147-c)=1258.1
6.5c+1455.3-9.9c=1258.10
(subtract 1455.3 from both sides)
6.4c-9.9c=-197.2
-3.4c=-197.2
(divide by -3.4 on both sides)
c=58
Hope this helps!! :D