document.write( "Question 334865: A truck driver traveled at 40 mph for the first part of a 646-mile trip, then increased his speed to 58 mph for the rest of the trip. The entire trip took 13 hours. How many hours are traveled at 58 mph? \n" ); document.write( "

Algebra.Com's Answer #240024 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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A truck driver traveled at 40 mph for the first part of a 646-mile trip,
\n" ); document.write( " then increased his speed to 58 mph for the rest of the trip.
\n" ); document.write( "The entire trip took 13 hours. How many hours are traveled at 58 mph?
\n" ); document.write( ":
\n" ); document.write( "let t = time traveled at 58 mph
\n" ); document.write( "then
\n" ); document.write( "(13-t) = time at 40 mph
\n" ); document.write( ":
\n" ); document.write( "Write a distance equation; dist = speed * time
\n" ); document.write( ";
\n" ); document.write( "40 mph dist + 58 mph dist = 646 mi
\n" ); document.write( "40(13-t) + 58t = 646
\n" ); document.write( ":
\n" ); document.write( "520 - 40t + 58t = 646
\n" ); document.write( "-40t + 58t = 646 - 520
\n" ); document.write( "18t = 126
\n" ); document.write( "t = $\"126%2F18\"$
\n" ); document.write( "t = 7 hrs at 58 mph
\n" ); document.write( ";
\n" ); document.write( ":
\n" ); document.write( "Check solution by finding the distances
\n" ); document.write( "13 - 7 = 6 hrs at 40 mph
\n" ); document.write( "40*6 + 58*7 =
\n" ); document.write( "240 + 406 = 646 \n" ); document.write( "

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