Answer:
f(n)=8n
Explanation:
As you can see by working 1 hour,2 hours,3hours Sam's earnings were respectively $8,$16,$24.
n=1,2,3,...(hours)
f(n)=Earnings by working n hours
f(1)=8×1=8
f(2)=8×2=16
f(3)=8×3=24
and so on
So, the correct answer is f(n)=8n