Algebra Word Problem?
On Tuesday, Malia drove to a conference and averaged 54mi/h for the trip. When she returned on thursday, road construction slowed her average speed by 9mi/h. If her total driving time was 11h, what was her driving time each way, and how far away from home was the conference?
How would I solve this problem? I know the answer but I don't know how to solve it.
Please Help!
Comments
Let d be the distance one way to the conference. Remember, d = rt. The distance both ways is the same:
54t1 = 45t2
Knowing that t1 + t2 = 11, we can substitute 11-t1 for t2:
54t1 = 45(11 - t1)
54t1 = 495 - 45t1
99t1 = 495
t1 = 5
Thus d = 54 * 5 = 270 miles.
Check: Total is11 hours, so t2 = 6 making distance 45 * 6 = 270. Yes, it is correct.
use x as unknown miles
54x + 45x = 11
99x = 11
x = 9