Let x represent the total amount of computers you sell in one year.
Since you get $50 for each computer, then, you would get 50x for x computers.
Additionally, your base salary is $24,000. Then, add 50x and 24,000 to find your total salary in a year.
If f(x) is a function that represents your salary depending on the amount of computers you sell, then:
Notice that the amount of computers that you sell cannot be a negative number. Then, you must take into account the following restriction:
Therefore, the answer is: