SOLUTION: Two cars start at the same place and travel at right angles to each other. one car travels 2mph faster than the other car after 2 hours they are 20 miles apart. how fast are the ca

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Question 907866: Two cars start at the same place and travel at right angles to each other. one car travels 2mph faster than the other car after 2 hours they are 20 miles apart. how fast are the cars traveling?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Two cars start at the same place and travel at right angles to each other.
one car travels 2mph faster than the other car
after 2 hours they are 20 miles apart.
how fast are the cars traveling?
:
let s = speed of the slower car
then
(s+2) = speed of the faster car
therefore:
2s = distance traveled by the slower car
and
2(s+2) = distance traveled by the faster car
:
We can solve this as right triangle: a^2 + b^2 = c^2, where
a = 2s
b = 2(s+2)
c = 20
%282s%29%5E2+%2B+%282%28s%2B2%29%29%5E2+=+20%5E2
4s%5E2+%2B+%282s%2B4%29%5E2+=+400
4s%5E2+%2B+4s%5E2+%2B+16s+%2B+16+=+400
8s%5E2+%2B+16s+%2B+16+-+400+=+0
8s%5E2+%2B+16s+-+384+=+0
simplify, divide by 8
s%5E2+%2B+2x+-+48+=+0
Factors to
(s+8)(s-6) = 0
The positive solution is all we want here
s = 6 mph is the speed of the slower car
:
you can find the speed of the faster car, check the solutions in original equation