Tonya’s dog-walking service charges a flat rate of $20 per month, plus $3 per mile that each dog is walked. Beth does not charge a monthly fee for her dog-walking service, but she charges $5 per mile that each dog is walked. Part A
Choose the equation that can be used to find the number of miles m for which Tonya and Beth would charge the same amount.

A. 20 + 3m = 5m
B. 20 = 3m + 5m
C. 20 + 5m = 3m
D. 20 + m = 8m