When Angie unplugged her phone from its charger this morning, its battery was almost fully
charged. The battery loses charge at a constant rate. The graph shows the linear relationship
between the time that passes, in hours, and the battery charge level.
10048
Battery charge level (percent)
90
B =
80
70
60
50
40
30
20
10
2 4 6 8 10 12 14 16 18 20
Time (hours)
Complete the equation to model the relationship between the battery charge level, B, and the
number of hours that pass, t.
t +
Complete the sentences to make true statements about the model.
The battery charge level when Angie unplugged her phone from its charger is
represented by the
which was
over time is represented by the
percent. The battery drain
percent per hour.
which is