document.write( "Question 587628: Jerry works 3 hours faster than David. Together they complete 5 jobs in 18 hours. How long does it take Jerry alone?\r
\n" ); document.write( "\n" ); document.write( "jerry = x
\n" ); document.write( "dave = x+3\r
\n" ); document.write( "\n" ); document.write( "1/x * 18 + (1/x+3) * 18 = 5\r
\n" ); document.write( "\n" ); document.write( "I think....but it just doesn't work how I think it should. I appreciate your help. \n" ); document.write( "
Algebra.Com's Answer #374166 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
Yes, you have it right.
\n" ); document.write( "1/x * 18 + (1/x+3) * 18 = 5
\n" ); document.write( "18/x + 18/(x+3) = 5
\n" ); document.write( "multiplying both sides by (x)(x+3):
\n" ); document.write( "18(x+3) + 18x = 5(x)(x+3)
\n" ); document.write( "18x+54 + 18x = 5(x^2+3x)
\n" ); document.write( "36x+54 = 5x^2+15x
\n" ); document.write( "54 = 5x^2-21x
\n" ); document.write( "0 = 5x^2-21x-54
\n" ); document.write( "0 = 5x^2-30x+9x-54
\n" ); document.write( "0 = (5x^2-30x) + (9x-54)
\n" ); document.write( "0 = 5x(x-6) + 9(x-6)
\n" ); document.write( "0 = (x-6)(5x+9)
\n" ); document.write( "x = {-9/5, 6}
\n" ); document.write( "throw out the negative solution (extraneous) leaving:
\n" ); document.write( "x = 6 hours\r
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