Hint for process of elimination: If we read carefully, we notice that the price of a single pair of shoes at the shoe store is $latex a &s=1$. The problem asks for the difference involving the cost of eight pairs of shoes at the shoe store. Therefore, the answer must have a term of $latex 8a &s=1$. This eliminates choices A, C, and E.
You can now try to reason through choices B and D. Since you eliminated three choices, you are statistically likely to improve your score by not leaving the answer blank, so you have to choose either B or D.
Read on for a full solution.
Solution: Let’s look more closely at one of the the sentences given:
…the eight pairs of shoes bought wholesale cost $latex c &s=1$ dollars less than eight pairs of shoes bought at the shoe store…
This is a word equation:
(the cost of eight pairs of shoes bought wholesale) [is] ($latex c &s=1$ dollars [less than]) (eight pairs of shoes bought at the shoe store)
The keyword “is” means “equals”, and the keyword “less than” means subtract at the end:
$latex b=8a-c &s=1$
Subtract $latex b &s=1$ from both sides to get
$latex 8a-b-c=0 &s=1$