12 packets in all
7 packets, 9 crayons
7×9=63 crayons
5 packets, 10 crayons
5×10=50 crayons
In all tells you to add all the previous numbers up
50+63= 113
The teacher bought 113 crayons in all.
Answer:

<h2>-19 is the right answer.</h2>
Y/z dosent belong on it I even think its not a number.Lol hope this helps :)
-1 is the answer hope that helps :D