Select the correct answer from each drop-down menu.

Gilbert is training for a bike race. As part of his training, he does practice rides on portions of the actual race course. Gilbert's first practice ride covers 5 miles of the course, and his second practice ride covers 9 miles of the course. Between these practice rides, he increases his average speed by 2 miles/hour.

These functions model the time it took Gilbert to do each practice ride, where [tex]$x$[/tex] is his speed during the first practice ride.

\begin{tabular}{|c|c|}
\hline Practice Ride 1 & Practice Ride 2 \\
\hline [tex]a(x)=\frac{5}{x}[/tex] & [tex]b(x)=\frac{9}{x+2}[/tex] \\
\hline
\end{tabular}

The denominator of the function that models practice ride 2 represents the [tex]$\square$[/tex].

To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, [tex]$\square$[/tex] the functions.



Answer :

Let's break down the solution into detailed steps for clarity:

1. Understanding the Functions:
- For Practice Ride 1, he covers [tex]\(5\)[/tex] miles at a speed of [tex]\(x\)[/tex] miles per hour:
[tex]\[ a(x) = \frac{5}{x} \][/tex]
This function gives the time in hours for the first practice ride.

- For Practice Ride 2, he covers [tex]\(9\)[/tex] miles at a speed of [tex]\(x + 2\)[/tex] miles per hour:
[tex]\[ b(x) = \frac{9}{x + 2} \][/tex]
This function gives the time in hours for the second practice ride.

2. Denominator of Practice Ride 2:
- The denominator of the function [tex]\(b(x) = \frac{9}{x + 2}\)[/tex] is [tex]\(x + 2\)[/tex], which represents Gilbert's speed during the second practice ride.

3. Total Time Function:
- To find the total time Gilbert spends on both practice rides, we need to add the time functions for Practice Ride 1 and Practice Ride 2.
- Therefore, the function that models the total amount of time Gilbert spent doing practice rides on the race course is:
[tex]\[ \text{total\_time}(x) = a(x) + b(x) = \frac{5}{x} + \frac{9}{x + 2} \][/tex]

Select the correct answer from each drop-down menu:
1. The denominator of the function that models practice ride 2 represents the speed during the second practice ride.
2. To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, add the functions.