Hello there. To solve this question, we'll have to remember some properties about inequalities.
We know company A charges $73 and allows unlimited mileage, while company B has an initial fee of $55 and charges an additional $0.90 for every mile driven.
First, we want to find how many dollars Lisa would spend in each case:
With company A, she would only spend $73, since this is the cost and she can drive unlimitedly.
With company B, say m is the number of miles driven. Then Lisa would spend $55 from the initial fee and $ 0.90 multiplied by m, that is
[tex]\$(55+0.90m)[/tex]Now, we want to find the values of m satisfying the inequality such that company A charge less than company B, namely
[tex]73<55+0.90m[/tex]Subtract 55 on both sides of the inequality
[tex]0.90m>18[/tex]Multiply both sides by a factor of 10
[tex]9m>180[/tex]Divide both sides by a factor of 9
[tex]m>20[/tex]These are the values of m such that company A will charge less than company B.