Answer:
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 $)
