Explanation:
For the brownie shop:
p = 200m - 2000
200m represents how much money you earn every month. 2000 is how much money you spent to start the business. Multiply 200 by the number of months, then add that number to -2000 to get your profit.
For the smoothie shop:
p = -200 -100m
Same thing as the brownie shop, but 200 is the money spent and 100 is the money earned. Both numbers are negative, so the profit will be more and more negative. This means that, unlike the brownie shop, the smoothie shop isn't gaining any money.