A pair of shoes costs customers $latex a &s=1$ dollars at the shoe store. The shoe store pays $latex b &s=1$ dollars for a box of eight pairs of shoes wholesale. If the cost of eight pairs of shoes purchased wholesale is $latex c &s=1$ dollars less than the cost of eight pairs of shoes at the shoe store, which of the following equations must be true?

1. $latex a-8b+c=0 &s=1$ (check answer)
2. $latex 8a-b+c=0 &s=1$ (check answer)
3. $latex a-b-c=0 &s=1$ (check answer)
4. $latex 8a-b-c=0 &s=1$ (check answer)
5. $latex a+8b-c=0 &s=1$ (check answer)

Solutions, hints, and questions are welcomed. A full solution will be posted on August 24th. If you would like to learn how to enter math formulas into this blog, visit the WordPress LaTeX tutorial page.