Emily is 280 miles away from home. She is traveling back at a rate of 40 miles per hour. Determine which graph and which equation represent Emily's distance from home, D, after Emily travels h hours.

Question

Emily is 280 miles away from home. She is traveling back at a rate of 40 miles per hour. Determine which graph and which equation represent Emily's distance from home, D, after Emily travels h hours.



Answer 1

Well, we know that distance is dependent on rate and time, so D is our dependent variable, which goes on the y-axis.

Since we are given the rate, our independent variable is h, the number of hours.

Since she starts 280 miles from home, at hour 0, the graph starts at 280 on the y-axis.

280/40 = 7 total hours, so at hour 7, she's home, meaning the other end of the graph is at 7 on the x-axis.

Hopefully you have a graph that matches this description.