Answer:

Step-by-step explanation:
Let, the number of blueberry slices = b and number of cherry slices = c.
As, each slice sells for the price of $3.50.
Thus, the revenue of total slices sold = 
Also, the money spent on ingredients of both the pie is $15.25 and $12.84 respectively.
Thus, the total selling cost of the slices = $15.25 + $12.84 = $28.09.
So, we have,
Cindy's profit = Revenue - Cost
i.e. Cindy's profit = 
Hence, the required expression is
.