Let x represent the number of miles driven by both individuals.
Now, since COMPANY A will charge Teresa an initial constant fee of $58 and then an additional 40 cents (or $0.4) for every mile driven, we know that:
- if Teresa drives x miles, she will be charged:

Therefore, in total, Teresa will be charged by company A the following:

Also, since COMPANY B will charge Teresa an initial constant fee of $40 and then an additional 69 cents (or $0.69) for every mile driven, we know that:
- if Teresa drives x miles, she will be charged:

Therefore, in total, Teresa will be charged by company B the following:

Now, the milieage (x) for which both companies A will charge Teresa no more than company does is obtained by relating the expressions for their separate fees as follows:

Thus, we simply the above and solve for x, as follows:

Collect like terms:

