document.write( "Question 158867: The OfficeJet printer can copy Maria's dissertation in 14 min. The LaserJet printer can copy the same document in 8 min. If the two machines work together, how long would they take to copy the dissertation? \n" ); document.write( "
Algebra.Com's Answer #117013 by ptaylor(2198)\"\" \"About 
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Let t=time it takes both machines working together to copy the dissertation
\n" ); document.write( "Officejet copies at the rate of 1/14 dissertaion per min
\n" ); document.write( "Laserjet copies at the rate 1/8 dissertaion per min\r
\n" ); document.write( "\n" ); document.write( "Together they copy at the rate of:
\n" ); document.write( "1/14 + 1/8 =4/56 + 7/56=11/56 dissertation per min
\n" ); document.write( "So, our equation to solve is:\r
\n" ); document.write( "\n" ); document.write( "(11/56)t=1 (1 dissertation, that is) multiply each side by 56
\n" ); document.write( "11t=56 divide each side by 11
\n" ); document.write( "t=5.09 min----time it takes both machines working together \r
\n" ); document.write( "\n" ); document.write( "Another way to look at it:
\n" ); document.write( "Together, the machines copy at the rate of 1/t dissertation per min, so:\r
\n" ); document.write( "\n" ); document.write( "1/14 + 1/8 =1/t multiply each term by 56t
\n" ); document.write( "4t+7t=56
\n" ); document.write( "11t=56----same as before\r
\n" ); document.write( "\n" ); document.write( "CK
\n" ); document.write( "(1/14)*5.09+(1/8)*5.09=1 multiply each term by 56
\n" ); document.write( "4*5.09+7*5.09=56
\n" ); document.write( "20.36 + 35.63=56
\n" ); document.write( "55.99~~~~~~56 roundoff error\r
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\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor\r
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