d = 21t
Explanation:Let the distance bicycled be represented by d
Let the time taken be represented by t
The direct variation between distance and time is:
d α t
Introducing a constant of proportionality, k
d = kt
distance, d = 42 miles
t = 2 hours
Substitute d = 42 and t = 2 into the equation d = kt in order to solve for k
42 = k(2)
k = 42/2
k = 21
Since k = 21, the direct variation equation becomes:
d = 21t
