Explore a wide range of topics and get answers from experts on IDNLearn.com. Find reliable solutions to your questions quickly and accurately with help from our dedicated community of experts.

Julissa is running a 10-kilometer race at a constant pace. After running for 18 minutes, she completes 2 kilometers. After running for 54 minutes, she completes 6 kilometers. Her trainer writes an equation letting [tex]$t$[/tex], the time in minutes, represent the independent variable and [tex]$k$[/tex], the number of kilometers, represent the dependent variable.

Which equation can be used to represent [tex]$k$[/tex], the number of kilometers Julissa runs in [tex]$t$[/tex] minutes?

A. [tex]$k - 2 = \frac{1}{9}(t - 18)$[/tex]
B. [tex]$k - 18 = \frac{1}{9}(t - 2)$[/tex]
C. [tex]$k - 2 = 9(t - 18)$[/tex]
D. [tex]$k - 18 = 9(t - 2)$[/tex]


Sagot :

Given the data points, we need to determine the correct equation to represent the number of kilometers [tex]\( k \)[/tex] Julissa runs in [tex]\( t \)[/tex] minutes.

We know the following:
- After 18 minutes, Julissa has run 2 kilometers.
- After 54 minutes, Julissa has run 6 kilometers.

First, let's determine the rate at which she is running. The formula for the rate (slope) is:
[tex]\[ \text{slope} = \frac{\Delta k}{\Delta t} = \frac{k_2 - k_1}{t_2 - t_1} \][/tex]
Plugging in the given values:
[tex]\[ \text{slope} = \frac{6 - 2}{54 - 18} = \frac{4}{36} = \frac{1}{9} \][/tex]

Now, using the point-slope form of the equation of a line, which is:
[tex]\[ k - k_1 = \text{slope} \times (t - t_1) \][/tex]
We can choose either of the points [tex]\((18, 2)\)[/tex] or [tex]\((54, 6)\)[/tex]. Let's use [tex]\((18, 2)\)[/tex] to derive the equation:
[tex]\[ k - 2 = \frac{1}{9} \times (t - 18) \][/tex]

Thus, the equation that represents [tex]\( k \)[/tex] is:
[tex]\[ k - 2 = \frac{1}{9}(t - 18) \][/tex]

Therefore, the correct equation is:
[tex]\[ k - 2 = \frac{1}{9}(t - 18) \][/tex]
We value your participation in this forum. Keep exploring, asking questions, and sharing your insights with the community. Together, we can find the best solutions. Your questions find answers at IDNLearn.com. Thanks for visiting, and come back for more accurate and reliable solutions.