Answer:
[tex] y = \dfrac{1}{20}x + 35 [/tex]
Step-by-step explanation:
Let y = cost.
Let x = number of miles.
We have two (x, y) points: (100, 40) and (220, 46).
Now we find the equation of the line that passes through those two points using the two-point form of the equation of a line.
[tex] y - y_1 = \dfrac{y_2 - y_1}{x_2 - x_1}(x - x_1) [/tex]
[tex] y - 40 = \dfrac{46 - 40}{220 - 100}(x - 100) [/tex]
[tex] y - 40 = \dfrac{6}{120}(x - 100) [/tex]
[tex] y - 40 = \dfrac{1}{20}(x - 100) [/tex]
[tex] y - 40 = \dfrac{1}{20}x - 5 [/tex]
[tex] y = \dfrac{1}{20}x + 35 [/tex]
