Answer:
The pet sitter babysat his dog for 3 hours.
Step-by-step explanation:
You know that a pet sitter charges $ 20 for supplies and $ 10 per hour of service, represented by the equation C = 10*n + 20, which describes the total cost she would charge for n hours of service.
The pet sitter charges a customer $ 50 for his service, so C has a value of $ 50.
Replacing:
50=10*n+20
Solving:
50 - 20= 10*n +20 -20
30= 10*n
30÷10= n
3= n
The pet sitter babysat his dog for 3 hours.
