The maximum number of miles that he can drive the car will be 300 miles.
Explanation
Suppose, the number of miles he can drive the car is [tex]x[/tex]
The car rents for $35 per day plus $0.21 per mile. So, the total cost for [tex]x[/tex] miles [tex]= (35+0.21x) dollar[/tex]
As he can spend no more than $98 per day, so.....
[tex]35+0.21x\leq 98\\ \\ 0.21x\leq 98-35\\ \\ 0.21x\leq 63\\ \\ x\leq \frac{63}{0.21}\\ \\ x\leq 300[/tex]
Thus, the maximum number of miles that he can drive the car will be 300 miles.
