Answer:
[tex]f(x) = \left \{ {{35x + 10, x \leq 3} \atop {35x + 5x = 40x, x>3}} \right.[/tex]
Step-by-step explanation:
Let x be the number of days you want to rent
The flat rate for car rental is $35 a day
As for insurance, $10 for 3 days or fewer, and $5 per day if more than 3 days that is
[tex]\left \{ {{10, x \leq 3} \atop {5x, x>3}} \right.[/tex]
Combine this with the flat rental rate $35 a day and we have
[tex]f(x) = \left \{ {{35x + 10, x \leq 3} \atop {35x + 5x = 40x, x>3}} \right.[/tex]