Question

A car that travels along the highway to Denver at a steady speed. When it begins, it is 300 miles from Denver. After 3 hours, it is 180 miles from Denver. Which function describes the car's distance from Denver?

Answer 1

Answer:

y==-40+160

Step-by-step explanation:

Answer 2

Answer:

$y=-40x+300$

Step-by-step explanation:

Let x be the time (in hours) and y be the distance from Denver (in miles).

When car begins, it is 300 miles from Denver, so x = 0 hours and y = 300 miles.

After 3 hours, it is 180 miles from Denver, then x = 3 hours and y = 180 miles.

Write the equation of the line passing through the points (0,300) and (3,180). The slope of this line is

$\dfrac{180-300}{3-0}=\dfrac{-120}{3}=-40$

y-intercept is at (0,300), hence the equation of the line is

$y=-40x+300$