Question 454984
Jill was going to meet Maria at the bus depot.
 If she went during rush hour, she traveled 15 mph and would arrive 1 hour later. 
If she went after rush hour, she traveled 30 mph and arrived an hour early.
:
Assume we are solving for the distance to bus station and the travel time to arrive on time
:
Let d = distance to the bus station
Let t = travel time to arrive on time
:
Write a distance equation for each scenario, arrange equations for elimination
Late:
15(t+1) = d
15t + 15 = d
15t - d = -15
:
Early
30(t-1) = d
30t - 30 = d
30t - d = 30
:
Subtract the 1st equation from the above equation
30t - d = 30
15t - d = -15
-----------------Subtraction eliminates d, find t
15t = 45
t = {{{45/15}}}
t = 3 hrs to get there on time
:
Find the distance using d = 15(t+1)
d = 15(3 + 1)
d = 15(4)
d = 60 mi to the bus station
:
Confirm this using d = 30(t-1)
d = 30(3-1)
d = 60 mi also