Question 1001778
The cost on the first rental is 0.7m  where m is miles driven
The cost for the second renatl is {{{75 + 0.5m}}}

To find the break even point

{{{0.7m = 75 + 0.5m}}}
{{{0.2m = 75}}}
{{{m = 75/ 0.2}}}
{{{m = 375}}}

If she is going to drive more than 375 miles, the second option is less expensive.