Here's the graph..........https://www.desmos.com/calculator/zysdb0bmhq
a) The "vertical" intercept is at (0, 9000) ad the "horizontal" intercept occurs at (15, 0)
b) The vertical intercept is interpreted as the distance remaining between the cities at the start of the flight [ where t = 0 ].....this is 9000 miles
The horizontal intercept is the number of hours it takes to complete the trip [ t = 15]....note that, at that time, the remaining distance between the cities = 0
c) The slope = -600.....this means that, for every hour of flight, the distance between the cities is lessened by 600 miles.....
Note the logic here : 15 hrs x 600miles per hour = 9000 miles of the whole trip covered
Hope that helps......
P.S. - In reality, Los Angeles to Boston is WAY LESS than 9000 miles !!!!
