ANSWER
For a mileage greater than 60 miles.
EXPLANATION
Let the number of miles be m.
Company A charges $129 while company B has an initial fee of $75 and charges an additional $0.90 for every mile driven.
We have to write an expression for the charges of Company B:
[tex]75+0.90m[/tex]For the charges of company A to be less than company B, it implies that:
[tex]129<75+0.90m[/tex]Solve from m in the inequality above:
[tex]\begin{gathered} 129-75<0.90m \\ \Rightarrow0.90m>54 \\ \frac{0.90m}{0.90}>\frac{54}{0.90} \\ \Rightarrow m>60 \end{gathered}[/tex]Therefore, the cost of Company A will be less than Company B when the mileage is more than 60 miles.