document.write( "Question 884936: suppose two trains leave a station at the same time, traveling in opposite directions. One train travels 20 miles faster than the other. In 2.5 hours the trains are 255 miles apart. Find the speed of the trains. \n" ); document.write( "
Algebra.Com's Answer #534809 by JulietG(1812)\"\" \"About 
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In 2.5 hours, the trains travel 255 miles. 255/2.5 = 102 miles per hour (combined speed).
\n" ); document.write( "A + B = 102
\n" ); document.write( "A = B + 20 [One train travels 20 miles faster than the other.]
\n" ); document.write( "Substitute the value of A from the second equation into the first.
\n" ); document.write( "A + B = 102
\n" ); document.write( "(B+20) + B = 102
\n" ); document.write( "Add
\n" ); document.write( "2B + 20 = 102
\n" ); document.write( "Subtract 20 from each side
\n" ); document.write( "2B = 82
\n" ); document.write( "Divide each side by 2
\n" ); document.write( "B = 41
\n" ); document.write( "If train B is traveling 41 mph, then train A is traveling 41+20, or 61 mph
\n" ); document.write( ".
\n" ); document.write( "Let's prove it.
\n" ); document.write( "Train A travels 61 mph for 2.5 hours. 61 * 2.5 = 152.5 miles
\n" ); document.write( "Train B travels 41 mph for 2.5 hours. 41 * 2.5 = 102.5 miles
\n" ); document.write( "Add them together: 152.5 + 102.5 = 255 miles \n" ); document.write( "
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