David's family is taking a road trip to Niagara Falls. His mom drove the first day, and his dad
is driving the second day. His dad's entire drive is on the freeway, and he drives at a constant
speed without stopping. The graph shows the linear relationship between the time, in hours,
David's dad spends driving and the total distance they have driven since leaving home.
Total distance (miles)
1,000
900
800
700
600
500
400
300
200
100
4
Time (hours)
Complete the equation to model the relationship between the total distance the family has
driven, D, and the time David's dad spends driving, t.
D =
1
t+
2
David's dad is driving
3
5
of
6
7
Complete the sentences to make true statements about the model.
miles.
8
9 10
miles per hour. This speed is represented by the
The distance David's mom drove is represented by the