Kieth is a furniture salesman. His weekly pay is $400 plus 4.5% of his total sales for the week. Kieth sells d dollars worth of furniture during the week. Which function ƒ (d) can be used to determine his pay for the week?

0.045d + 400 (in $)

Step-by-step explanation:

Given that his weekly pay is $400 plus 4.5% of his total sales for the week. It means that his weekly earnings has a fixed and a variable part. The fixed being $400 and the variable being 4.5% of d dollars where he sold d dollars worth of furniture during the week.

As such, the function ƒ (d) that can be used to determine his pay for the week

= $400 + 4.5% * $d

= 0.045d + 400 (in $)