Hey there!
This situation can be represented by the following function:
3.50x + 55y = z, where
x is the number of fish sold
y is the number of tanks sold, and
z is total amount of money earned.
You would then plug in your numbers to find the total amount of profit that can be earned on the current amount of items the store has.
3.50x + 55y = z
3.50(362) + 55(15) = z
1,267 + 825 = z
2,092 = z
A total of $2,092.00 can be made off of the current stock. Hope this helped you out! :-)