document.write( "Question 1109251: a truck driver drives from city A to city B in 5hr at a certain average speed and drives back from city B to city A in 4 hr at an average speed of 15 miles per faster, which of the following is the truck driver average speed from city A to city B \n" ); document.write( "
Algebra.Com's Answer #724242 by ankor@dixie-net.com(22740)\"\" \"About 
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A truck driver drives from city A to city B in 5 hr at a certain average speed and drives back from city B to city A in 4 hr at an average speed of 15 miles per faster, what is the truck driver average speed from city A to city B
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\n" ); document.write( "let s = his speed from A to B
\n" ); document.write( "then
\n" ); document.write( "(s+15) = his speed from B to A
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\n" ); document.write( "The distance is the same each way, write a dist equation dist = time * speed
\n" ); document.write( "5s = 4(s+15)
\n" ); document.write( "5s = 4s + 60
\n" ); document.write( "5s - 4s = 60
\n" ); document.write( "s = 60 mph is his speed from A to B
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\n" ); document.write( "Confirm this, find the actual distance (return speed 60+15)
\n" ); document.write( "5 * 60 = 300 mi
\n" ); document.write( "4 * 75 = 300 mI \n" ); document.write( "
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