Given that,
base salary = b = 5000$
Comission rate = 6% = 0.06
Let's say, the sales are = x
As given in the question, he receives 6% commission on all sales over $8000.
Hence, the commissionable amount is (x - 8000) '.' x - 8000 shows the amount greater than 8000, which receives a commission.
hence, gross income will be
base salary + commission * (commisonable amount)
=> 5000 + 0.06 * (x - 8000)
