document.write( "Question 691561: Jose and Carl together can retile a roof in 10 hours. Working alone, Jose could do the job 4.5 hours faster than Carl. How long would each man need to work to do the job himself? \n" ); document.write( "

Algebra.Com's Answer #426770 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Jose and Carl together can retile a roof in 10 hours.
\n" ); document.write( " Working alone, Jose could do the job 4.5 hours faster than Carl.
\n" ); document.write( " How long would each man need to work to do the job himself?
\n" ); document.write( ":
\n" ); document.write( "Let j = Jose's time to do the job
\n" ); document.write( "then
\n" ); document.write( "(j+4.5) = Carl's time
\n" ); document.write( ":
\n" ); document.write( "Let the competed job = 1
\n" ); document.write( ":
\n" ); document.write( " $\"10%2Fj\"$ + $\"10%2F%28%28j%2B4.5%29%29\"$ = 1
\n" ); document.write( "multiply by j(j+4.5) to clear the denominators, results:
\n" ); document.write( "10(j+4.5) + 10j = j(j+4.5)
\n" ); document.write( "10j + 45 + 10j = j^2 + 4.5j
\n" ); document.write( "A quadratic equation
\n" ); document.write( "0 = j^2 + 4.5j - 20j -45
\n" ); document.write( "j^2 - 15.5j - 45 = 0
\n" ); document.write( ":
\n" ); document.write( "solve this, the positive solution; j = 18 hrs \n" ); document.write( "

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