document.write( "Question 1204175: P can complete a task in x days while Q takes (x + 12) days to do the same task.
\n" ); document.write( "a) What fraction of the task can each of them complete in a day?
\n" ); document.write( "b) If both of them work together, they can
\n" ); document.write( "complete the task in 8 days. Find x.
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Algebra.Com's Answer #840251 by Theo(13342)\"\" \"About 
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let p = the rate that P works per day.
\n" ); document.write( "let q = the rate that Q works per day.\r
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\n" ); document.write( "\n" ); document.write( "rate * time = quantity.\r
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\n" ); document.write( "\n" ); document.write( "for P, you get p * x = 1, resulting in p = 1/x
\n" ); document.write( "for Q, you get q * (x + 12) = 1, resulting in q = 1/(x + 12).\r
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\n" ); document.write( "\n" ); document.write( "you are given that they can both complete the task in 8 days when working together.
\n" ); document.write( "the equation for that is 8 * (p + q) = 1
\n" ); document.write( "simplify to get 8p + 8q = 1\r
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\n" ); document.write( "\n" ); document.write( "since p = 1/x and q = 1/(x + 12), you get:
\n" ); document.write( "8 * 1/x + 8 * 1/(x + 12) = 1
\n" ); document.write( "simplify to get 8/x + 8/(x + 12) = 1
\n" ); document.write( "multiply both sides of this equation by x * (x + 12) to get:
\n" ); document.write( "8 * (x + 12) + 8 * x = x * (x + 12)
\n" ); document.write( "simplify to get:
\n" ); document.write( "8x + 96 + 8x = x^2 + 12x
\n" ); document.write( "combine like terms to get:
\n" ); document.write( "16x + 96 = x^2 + 12x
\n" ); document.write( "subtract the left side of the equation from both sides of the equation to get:
\n" ); document.write( "0 = x^2 + 12x - 16x - 96
\n" ); document.write( "combine like terms to get:
\n" ); document.write( "0 = x^2 - 4x - 96
\n" ); document.write( "solve this quadratic equation to get:
\n" ); document.write( "x = 12 or x = -8.\r
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\n" ); document.write( "\n" ); document.write( "since x has to be positive, then x = 12.
\n" ); document.write( "since p = 1/x, then p = 1/12
\n" ); document.write( "since q = 1/(x + 12), then q = 1/24\r
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\n" ); document.write( "\n" ); document.write( "since 8p + 8q = 1, then replace p and q with their respective values to get:
\n" ); document.write( "8 * 1/12 + 8 * 1/24 = 1
\n" ); document.write( "simplify to get 8/12 + 8/24 = 1
\n" ); document.write( "simplify further to get 1 = 1, confirming the value of p and q are good.\r
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\n" ); document.write( "\n" ); document.write( "answers to your questions are:\r
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\n" ); document.write( "\n" ); document.write( "a) What fraction of the task can each of them complete in a day?\r
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\n" ); document.write( "\n" ); document.write( "P can complete 1/12 of the task in one day.
\n" ); document.write( "Q can complete 1/24 of the taxk in one day.\r
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\n" ); document.write( "\n" ); document.write( "b) If both of them work together, they can complete the task in 8 days. Find x.\r
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\n" ); document.write( "\n" ); document.write( "x is equal to 12.\r
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