David is going to rent a truck for one day. There are two companies he can choose from, and they have the following prices.
Company $A$ charges $\mathrm{\$}79$ and allows unlimited mileage.
Company $B$ has an initial fee of $\mathrm{\$}65$ and charges an additional $\mathrm{\$}0.70$ for every mile driven.
For what mileages will Company A charge less than Company B?
Use $m$ for the number of miles driven, and solve your inequality for $m$.

Step 1 ：David is considering renting a truck for one day from either Company A or Company B. Company A charges a flat rate of $79withunlimitedmileage,whileCompanyBchargesaninitialfeeof$65 and an additional $0.70 for every mile driven.

Step 2 ：We need to find the number of miles for which the cost of renting from company A is less than the cost of renting from company B. This can be represented by the inequality $79<65+0.7m$, where $m$ represents the number of miles driven.

Step 3 ：Solving the inequality for $m$, we get $m>20.0$.

Step 4 ：This means that for any mileage greater than 20 miles, company A will charge less than company B. Therefore, David should choose company A if he plans to drive more than 20 miles.

Step 5 ：$\boxed{{\displaystyle m>20}}$ is the final answer. For mileages greater than 20 miles, company A will charge less than company B.