document.write( "Question 581117: Increasing the average speed of the Pickerington Express Bus by 13 km/h resulted in the 260 km trip taking a hour less than before. What was the original average speed of the bus? \n" ); document.write( "

Algebra.Com's Answer #371509 by mananth(16946) $\"\"$ $\"About$

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let the original speed of the bus be x\r
\n" ); document.write( "\n" ); document.write( "speed increased by 13 km/h , x+13\r
\n" ); document.write( "\n" ); document.write( "distance = 260\r
\n" ); document.write( "\n" ); document.write( "original time = new time + 1\r
\n" ); document.write( "\n" ); document.write( "original time - new time = 1\r
\n" ); document.write( "\n" ); document.write( "t=d/r
\n" ); document.write( "260/x - 260/(x+13)=1\r
\n" ); document.write( "\n" ); document.write( "LCD = x(x+13)\r
\n" ); document.write( "\n" ); document.write( "multiply by the LCD\r
\n" ); document.write( "\n" ); document.write( "260(x+13) -260x= x(x+13)\r
\n" ); document.write( "\n" ); document.write( "260x+3380-260x=x^2+13x\r
\n" ); document.write( "\n" ); document.write( "x^2+13x-3380=0\r
\n" ); document.write( "\n" ); document.write( "x^2+65x-52x-3380=0\r
\n" ); document.write( "\n" ); document.write( "x(x+65)-52(x+65)=0\r
\n" ); document.write( "\n" ); document.write( "(x-52)(x+65)=0\r
\n" ); document.write( "\n" ); document.write( "x= 52 km/h the original speed\r
\n" ); document.write( "\n" ); document.write( "we ignore the negative value x=-65 \n" ); document.write( "

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