Step-by-step explanation: Firstly, you have to account for how much money Rafael is making off of each computer (800 - 450). That factor is then multiplied by the variable "n" which represents the amount of computers sold. Lastly, since this is an equation to calculate his monthly profits, you have to subtract the rent that he is paying ($3000) from the total profit that he made off of selling the computers. Therefore, giving you the equation
P (profit) = n (amount of computers sold) (800-450) - 3000 (rent).
