Answer :
Let's break down each part of the question step-by-step:
### Denominator of Practice Ride 2
For Gilbert's second practice ride, the function modeling his time is given by [tex]\( b(x) = \frac{9}{x+2} \)[/tex], where [tex]\( x \)[/tex] represents his speed during the first ride. The denominator here is [tex]\( x+2 \)[/tex], which represents Gilbert's speed on the second ride increased by 2 miles/hour. This means that his speed during his second ride is 2 miles/hour more than his speed during the first ride.
### Total Time Function
To determine the total time Gilbert spent on his practice rides, we need to sum the times for each ride. The functions for each ride are:
- Practice Ride 1: [tex]\( a(x) = \frac{5}{x} \)[/tex]
- Practice Ride 2: [tex]\( b(x) = \frac{9}{x+2} \)[/tex]
Thus, the total time function [tex]\( T(x) \)[/tex] is the sum of these two functions:
[tex]\[ T(x) = a(x) + b(x) = \frac{5}{x} + \frac{9}{x+2} \][/tex]
### Filling in the Blanks
1. The denominator of the function that models practice ride 2 represents __the speed increased by 2 miles/hour__.
2. To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, __sum__ the functions.
Therefore, the correct selections are:
- The denominator of the function that models practice ride 2 represents the speed increased by 2 miles/hour.
- To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, sum the functions.
### Denominator of Practice Ride 2
For Gilbert's second practice ride, the function modeling his time is given by [tex]\( b(x) = \frac{9}{x+2} \)[/tex], where [tex]\( x \)[/tex] represents his speed during the first ride. The denominator here is [tex]\( x+2 \)[/tex], which represents Gilbert's speed on the second ride increased by 2 miles/hour. This means that his speed during his second ride is 2 miles/hour more than his speed during the first ride.
### Total Time Function
To determine the total time Gilbert spent on his practice rides, we need to sum the times for each ride. The functions for each ride are:
- Practice Ride 1: [tex]\( a(x) = \frac{5}{x} \)[/tex]
- Practice Ride 2: [tex]\( b(x) = \frac{9}{x+2} \)[/tex]
Thus, the total time function [tex]\( T(x) \)[/tex] is the sum of these two functions:
[tex]\[ T(x) = a(x) + b(x) = \frac{5}{x} + \frac{9}{x+2} \][/tex]
### Filling in the Blanks
1. The denominator of the function that models practice ride 2 represents __the speed increased by 2 miles/hour__.
2. To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, __sum__ the functions.
Therefore, the correct selections are:
- The denominator of the function that models practice ride 2 represents the speed increased by 2 miles/hour.
- To find a function that models the total amount of time Gilbert spent doing practice rides on the race course, sum the functions.