Question 1128849
Thaddeus and Ian start at the same location and drive in opposite​ directions, but leave at different times.
 When they are 275 miles​ apart, their combined travel time is 12 hours.
 If Thaddeus drives at a rate of 20 miles per hour and Ian drives at a rate of 25 miles per​ hour,
 how long had each been​ driving?
:
let t = Thad's travel time
their total is 12 hrs, therefore
(12-t) = Ian's travel time
:
Write a dist equation; dist = speed*time
20t + 25(12-t) = 275
20t + 300 - 25t = 275
20t - 25t = 275 - 300
-5t = -25
t = -25/-5
t = +5 hrs is Thad's travel time
then obviously
12-5 = 7 hrs is Ian's
:
;
Check, find the actual dist each traveled
20(5) = 100 mi
25(7) = 175 mi
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tot dist 275