SOLUTION: It took Debbie 5.4 hours to drive to her mother's house on Thursday. On her returning trip on Friday night, traffic was heavier so the trip took her 6 hours. Her average speed on F

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Question 734467: It took Debbie 5.4 hours to drive to her mother's house on Thursday. On her returning trip on Friday night, traffic was heavier so the trip took her 6 hours. Her average speed on Friday was 6 mph slower than on Thursday. What was her average speed on Friday?
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT
D=R*5.4
D=(R-6)6
5.4R=(R-6)6
5.4R=6R-36
5.4R-6R=-36
-.6R=-36
R=-36/-.6
R=60 MPH WAS HER SPEED ON THE FIRST TRIP.
60-6=54 MPH. WAS HER SPEED ON THE FRIDAY TRIP.
PROOF:
60*5.4=54*6
324=324