document.write( "Question 602226: Larry and Margee can paint a room in 7 hours. If Margee worked alone it would take her 3 hours longer than if Larry worked alone. How long would it take each person if they worked alone? \n" ); document.write( "
Algebra.Com's Answer #380336 by ankor@dixie-net.com(22740)\"\" \"About 
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Larry and Margee can paint a room in 7 hours.
\n" ); document.write( " If Margee worked alone it would take her 3 hours longer than if Larry worked alone.
\n" ); document.write( " How long would it take each person if they worked alone?
\n" ); document.write( ":
\n" ); document.write( "Let t = L's time to do the job alone
\n" ); document.write( "then
\n" ); document.write( "(t=3) = M's time to do it
\n" ); document.write( ":
\n" ); document.write( "Let completed job = 1 (a painted room)
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\n" ); document.write( "\"7%2Ft\" + \"7%2F%28%28t%2B3%29%29\" = 1
\n" ); document.write( ":
\n" ); document.write( "Multiply by t(t+3) to clear the denominators, results
\n" ); document.write( "7(t+3) + 7t = t(t+3)
\n" ); document.write( "7t + 21 + 7t = t^2 + 3t
\n" ); document.write( "14t + 21 = t^2 + 3t
\n" ); document.write( "0 = t^2 + 3t - 14t - 21
\n" ); document.write( "A quadratic equation
\n" ); document.write( "t^2 - 11t - 21 = 0
\n" ); document.write( "use the quadratic formula to find t
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "In this equation: x=t; a=1; b=-11; c=-21
\n" ); document.write( "\"t+=+%28-%28-11%29+%2B-+sqrt%28-11%5E2-4%2A1%2A-21+%29%29%2F%282%2A1%29+\"
\n" ); document.write( ":
\n" ); document.write( "\"t+=+%2811+%2B-+sqrt%28121%2B84+%29%29%2F2+\"
\n" ); document.write( ":
\n" ); document.write( "\"t+=+%2811+%2B-+sqrt%28205+%29%29%2F2+\"
\n" ); document.write( "The positive solution
\n" ); document.write( "\"t+=+%2811+%2B+14.3%29%2F2+\"
\n" ); document.write( "t = \"25.3%2F2\"
\n" ); document.write( "t = 12.65 hrs, time L takes working alone
\n" ); document.write( "then
\n" ); document.write( "12.65+3 = 15.65 hrs, time M takes working alone
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