Final answer:
Bobby can buy the most expensive item for $46.75 and stay within his budget of $85 with a 45% discount.
Step-by-step explanation:
To find the most expensive item Bobby can buy and stay within his budget, we need to calculate the discount amount first. The store has a 45% discount, so we can find the discount amount by multiplying $85 by 45% (which is 0.45). The discount amount is $38.25 ($85 x 0.45 = $38.25). To find the maximum price Bobby can afford, we subtract the discount amount from his budget: $85 - $38.25 = $46.75.
Therefore, the most expensive item Bobby can buy and stay within his budget is $46.75.