SOLUTION: when Mr. Tesla drives 60 miles an hour the commute from home to office is 30 minutes less than when he drives 40 miles an hour from home to office.what is the distance of nr tesla

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Question 1138946: when Mr. Tesla drives 60 miles an hour the commute from home to office is 30 minutes less than when he drives 40 miles an hour from home to office.what is the distance of nr tesla commute from home to office?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +t+ = time in hrs for the 40 mi/hr drive
+t+-+.5+ = time in hrs for the 60 mi/hr drive
Let +d+ = distance from home to office
----------------------------------------------------
(1) +d+=+40t+
(2) +d+=+60%2A%28+t+-+.5+%29+
---------------------------------
(2) +d+=+60t+-+30+
By substitution:
(2) +40t+=+60t+-+30+
(2) +20t+=+30+
(2) +t+=+1.5+
and
(1) +d+=+40%2A1.5+
(1) +d+=+60+
The distance from home to office is 60 mi
check:
(2) +d+=+60%2A%28+t+-+.5+%29+
(2) +60+=+60%2A%28+1.5+-+.5+%29+
(2) +60+=+60+
OK