I think this might help but sorry if it does not but I hope it does :) :D - https://learnzillion.com/lesson_plans/5701-writing-an-explicit-formula-for-the-graph-of-an-exponential-relationship/
$4.20 / 36 = $0.11667 per potato<span>
</span>
892.48
You have to subtract he given numbers.
The answer is 25!
3 times 7 = 21 + 4 = 25
