Jane drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 10 hours. When Jane drove home, there was no traffic and the trip only took 7 hours. If her average rate was 18 miles per hour faster on the trip home, how far away does Jane live from the mountains?
Solution
On the way to the mountains
d = ? v = ? t = 10 hours
d = 10v
On the way home
d = ? v + 18 t = 7 hours
d = (v + 18) x 7
The distance the house is from the mountains is the same, so we can set the two equation equal to each other
10v = (v+18) x 7
10v = 7v + 126
10v - 7v = 126
3v = 126
v = 126/3 = 42
d = (v + 18) x 7
d = (42 + 18) x 7
d = 60 x 7
d = 420
Jane lives 420 miles away from the mountains
Sep 25, 17 09:22 AM
Writing an algebraic expression when a phrase is given is the goal of this lesson
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