document.write( "Question 667755: A train moving at r miles/hour can cover a given distance in h hours. By how many minute/hour must its speed be increased in order to cover the same distance in one hour less time? \n" ); document.write( "

Algebra.Com's Answer #415178 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
A train moving at r miles/hour can cover a given distance in h hours.
\n" ); document.write( " By how many minute/hour must its speed be increased in order to cover the
\n" ); document.write( " same distance in one hour less time?
\n" ); document.write( ":
\n" ); document.write( "We will use mph for speed.
\n" ); document.write( ":
\n" ); document.write( "Distance covered can be written as rh (rate*time)
\n" ); document.write( ":
\n" ); document.write( "let a = additional speed required to cover the same distance in 1 hr less
\n" ); document.write( ":
\n" ); document.write( "(r+a)*(h-1) = rh
\n" ); document.write( "FOIL
\n" ); document.write( "rh - r + ah - a = rh
\n" ); document.write( "subtract rh from both sides
\n" ); document.write( "-r + ah - a = 0
\n" ); document.write( "ah - a = r
\n" ); document.write( "a(h-1) = r
\n" ); document.write( "a = $\"r%2F%28%28h-1%29%29\"$ mph; additional speed to accomplish this
\n" ); document.write( " \n" ); document.write( "

\n" );