Answer: He will earn about $120 if he walks 13 single dogs and 9 sets of two dogs .
Step-by-step explanation:
Given : Brian's going to charge each dog owner $4.50 to walk one dog and $6.75 to walk two dogs.
If he walks 13 single dogs , then amount earned = 13 × $4.50
= $58.5 (1)
If he walks 9 sets of two dogs, then amount earned = 9 × $6.75
=$60.75 (2)
Add (1) and (2)
The total amount he earned = $58.5 + $60.75
= $119.25 ≈ $120
Hence, he will earn about $120 if he walks 13 single dogs and 9 sets of two dogs .
