document.write( "Question 535236: A car traveled 462 km in 7 h. for the last 3 h of the trip its average speed was 20 km/h less than twice its average speed for the first 4 h. find the two speeds at which the car traveled. (using uniform motion) \n" ); document.write( "
Algebra.Com's Answer #351895 by ankor@dixie-net.com(22740)\"\" \"About 
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A car traveled 462 km in 7 h. for the last 3 h of the trip its average speed was 20 km/h less than twice its average speed for the first 4 h.
\n" ); document.write( " find the two speeds at which the car traveled. (using uniform motion)
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\n" ); document.write( "Let s = car speed the 1st 4 hrs
\n" ); document.write( "then
\n" ); document.write( "(2s-20) = speed the last 3 hrs\"
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\n" ); document.write( "Write a distance equation; dist = speed * time
\n" ); document.write( ":
\n" ); document.write( "4s + 3(2s-20) = 462
\n" ); document.write( "4s + 6s - 60 = 462
\n" ); document.write( "10s = 462 + 60
\n" ); document.write( "10s = 522
\n" ); document.write( "s = 522/10
\n" ); document.write( "s = 52.2 km/hr the 1st 4 hrs
\n" ); document.write( "then
\n" ); document.write( "2(52.2) - 20 = 84.4 km/hr the last 3 hrs
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\n" ); document.write( "You can check these solutions, find the distance at each speed, should equal 462 km \n" ); document.write( "
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