Algebra
posted by Roger
Austin drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took
8 hours. When Austin drove home, there was no traffic and the trip only took
5 hours. If his average rate was
21 miles per hour faster on the trip home, how far away does Austin live from the mountains?
Do not do any rounding.

Reiny
speed on first leg  x mph
speed on return trip  x+21 mph
distance on first leg = 8x
distance for return leg = 5(x+21)
but the distances are equal, so
8x = 5(x+21)
8x = 5x + 105
3x=105
x = 35
distance = 8(35) = 280 miles 
Reiny
Just realized I did this same question a few weeks back
http://www.jiskha.com/display.cgi?id=1443062344
Respond to this Question
Similar Questions

math
A family drove 1080 miles to their vacation lodge. Because of increased traffic density, their average speed on the return trip was decreased by 6 miles per hour and the trip took 2.5 hours longer. Determine their average speed on … 
math
A family drove 1080 miles to their vacation lodge. Because of increased traffic density, their average speed on the return trip was decreased by 6 miles per hour and the trip took 2.5 hours longer. Determine their average speed on … 
physics
A student wanted to drive from Austin to san Antonio ,80 mi south of Austin on highway I35. Unfortunately he entered in the wrong direction and drove to waco100 miles north of Austin –before he noticed his error. In waco ,he turned … 
College Algebra
A family drove 1080 miles to their vacation lodge. Because of increased traffic density, their average speed on the return trip was decreased by 6 miles per hour and the trip took 2.5 hours longer. Determine their average speed on … 
physics
student wanted to drive from Austin to San Antonio, 80 miles south of Austin on highway I35. Unfortunately, he entered the highway in the wrong direction and drove all the way to Waco — 100 miles north of Austin — before he noticed … 
Math
Patrick drove 3 hours to attend a meeting. on the return trip, his speed was 10 mi/h less, and the trip took 4 hours. a) what was his speed each way? 
math
Serena's parents drove her to Gulf Coast Beach.The trip from home to the beach took 2 1/2 hours at an average of 56mph.On the return trip,they drove at an average of 60mph.H ow far is the beach from their home? 
math
Laura drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 6 hours. When Laura drove home, there was no traffic and the trip only took 4 hours. If her average rate was 22 miles per hour faster … 
math
Rueben drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 7 hours. When Rueben drove home, there was no traffic and the trip only took 5 hours. If his average rate was 18 miles per hour … 
algebra
alberto drove to the lake and back. the trip there took two hours and the trip back took three hours. he averaged 20 km/h faster on the trip there than on the return trip. What was alberto's average speed on the outbound trip?