SOLUTION: Maria and Jody start to travel in the same direction from the same pont. Maria drives 30 mph faster than Jody. How long will it take Maria to have 45 miles in between them?

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Question 478379: Maria and Jody start to travel in the same direction from the same pont. Maria drives 30 mph faster than Jody. How long will it take Maria to have 45 miles in between them?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let s = Jody's speed
Let t = the time elapsed until
they are 45 mi apart
Maria's equation:
(1) +d+=+%28+s+%2B+30+%29%2At+
Jody's equation:
(2) +d+-+45+=+s%2At+
-----------------
Substitute (2) into (1)
(1) +d+=+s%2At++%2B+30t+
(1) +d+=+d+-+45+%2B+30t+
Subtract d from both sides
(1) +45+=+30t+
(1) +t+=+1.5+
It will take 1.5 hrs
check answer:
(1) +d+=+%28s+%2B+30%29%2At+
(1) +d+=+1.5s+%2B+45+
and
(2) +1.5s+%2B+45++-+45+=+1.5s+
OK