document.write( "Question 600979: During the first part of a trip, a canoeist travels 45 miles at a certain speed. The canoeist travels 20 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 2 hrs. What was the speed on each part of the trip?
\n" ); document.write( "The speed on the first part of the trip was _______ mph.
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Algebra.Com's Answer #379598 by ankor@dixie-net.com(22740)\"\" \"About 
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During the first part of a trip, a canoeist travels 45 miles at a certain speed.
\n" ); document.write( " The canoeist travels 20 miles on the second part of the trip at a speed 5 mph slower.
\n" ); document.write( " The total time for the trip is 2 hrs. What was the speed on each part of the trip?
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\n" ); document.write( "Let s = speed the first part of the trip
\n" ); document.write( "and
\n" ); document.write( "(s-5) = speed on the 2nd part
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\n" ); document.write( "Write a time equation: time = dist/speed
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\n" ); document.write( "1st part time + 2nd part time = 2 hrs
\n" ); document.write( "\"45%2Fs\" + \"20%2F%28%28s-5%29%29\" = 2
\n" ); document.write( "multiply by s(s-5) to clear the denominators, results:
\n" ); document.write( "45(s-5) + 20s = 2s(s-5)
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\n" ); document.write( "45s - 225 + 20s = 2s^2 - 10s
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\n" ); document.write( "65s - 225 = 2s^2 - 10s
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\n" ); document.write( "0 = 2s^2 - 10s - 65s + 225
\n" ); document.write( "A quadratic equation
\n" ); document.write( "2s^2 - 75s + 225 = 0
\n" ); document.write( "Use the quadratic formula to fins s
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "In this equation: x=s; a=2; b=-75; c=225
\n" ); document.write( "\"s+=+%28-%28-75%29+%2B-+sqrt%28-75%5E2-4%2A2%2A225+%29%29%2F%282%2A2%29+\"
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\n" ); document.write( "\"s+=+%2875+%2B-+sqrt%285625-1800+%29%29%2F4+\"
\n" ); document.write( ":
\n" ); document.write( "\"s+=+%2875+%2B-+sqrt%283825+%29%29%2F4+\"
\n" ); document.write( "Two solutions, but only this one makes sense.
\n" ); document.write( "\"s+=+%2875+%2B+61.85%29%2F4+\"
\n" ); document.write( "s = \"136.84%2F4\"
\n" ); document.write( "s = 34.2 mph on the 1st part of the trip
\n" ); document.write( "and
\n" ); document.write( "34.2 - 5 = 29.2 mph on the 2nd part
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\n" ); document.write( "Let's see if this checks out, find sum of the times at each speed
\n" ); document.write( "45/34.2 = 1.3158 hrs at 34.2 mph
\n" ); document.write( "20/29.2 = 0.6849 hrs at 29.2 mph
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\n" ); document.write( "tot time: 2.0007 hrs which is the total time
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