Answer: 5m + 20 miles
Explanation:
Miles driven on first day = m
On the second day, they drive five more miles than they did on the first day. This will be: = m + 5
On the third day, they drove three times as many miles as they did on the second day. This will be:
= 3(m + 5)
= 3m + 15
Total miles driven will now be:
= m + m+5 + 3m + 15
= 5m + 20