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-9 -8-7-6-5-4-3-2-1 0 1 2 3 4 5 6
Explanation: for A
Start with the negative 9 and add 15
Do the same thing for b and c.
For b begin with -9 and go down to the left 15 more spaces you should wind up -24
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-24-23-22-21-20-19-18-17-16-15-14-13-12 etc
For c begin with positive 9 and subtract to the left 15 spaces
