document.write( "Question 184018: Trimming hedges.
\n" ); document.write( "Lourdes can trim the hedges around her property in 8 hours by using an electric hedge trimmer. Rafael can do the same job in 15 hours by using a manual trimmer. How long would it take them to trim the hedges working together? \n" ); document.write( "
Algebra.Com's Answer #138047 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Lourdes can trim the hedges around her property in 8 hours by using an electric hedge trimmer. Rafael can do the same job in 15 hours by using a manual trimmer. How long would it take them to trim the hedges working together?
\n" ); document.write( "----------------
\n" ); document.write( "Lourdes DATA:
\n" ); document.write( "time = 8 hr/job ; rate = 1/8 job/hr.
\n" ); document.write( "---------------------------------------
\n" ); document.write( "Rafael DATA:
\n" ); document.write( "time = 15 hr/job ; rate = 1/15 job/hr.
\n" ); document.write( "---------------------------------------
\n" ); document.write( "Together DATA:
\n" ); document.write( "time = x hr/job ; rate = 1/x job/hr
\n" ); document.write( "=======================================
\n" ); document.write( "Equation:
\n" ); document.write( "rate + rate = together rate
\n" ); document.write( "1/8 + 1/15 = 1/x\r
\n" ); document.write( "\n" ); document.write( "Multiply thru by 120x to get:
\n" ); document.write( "15x + 8x= 120
\n" ); document.write( "23x = 120
\n" ); document.write( "x = 5.21 hrs (time to trim the hedges together)
\n" ); document.write( "====================================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( " \n" ); document.write( "
\n" );