Answer: The equation models the data is given by
[tex]c=3d[/tex]
Step-by-step explanation:
Since we have given that
Days Cost
2 6
3 9
5 15
6 18
Let the number of days be 'd'.
Let the cost be 'c'.
So, we can see that there is direct variation between d and c :
[tex]\dfrac{d}{c}=\dfrac{2}{6}\\\\\dfrac{d}{c}=\dfrac{1}{3}\\\\c=3d[/tex]
Hence, the equation models the data is given by
[tex]c=3d[/tex]