Answer: you will save with plan B for miles greater than 153.8 miles.
Step-by-step explanation:
Let x represent the number of miles driven with either plans per day.
Plan A: 30 dollars per day and 13 cents per mile. Converting cents to dollars, it becomes 13/100 = $0.13. It means that the total cost of driving x miles with plan A is
30 + 0.13x
Plan B: 50 dollars per day with free unlimited mileage. It means that the total cost of driving x miles with plan B is 50 dollars
For you to save money with plan B, it means that the number of miles would be
50 < 30 + 0.13x
50 - 30 < 0.13x
20 < 0.13x
0.13x > 20
x > 20/0.13
x > 153.8
