document.write( "Question 1045207: 2 men and 5 boys can do a piece of work in 4 days, while 4 men and 4 boys can do it in 3 days how long would it take one man alone to do it and how many days would it take one boy alone to do it? \n" ); document.write( "
Algebra.Com's Answer #660599 by josgarithmetic(39617)\"\" \"About 
You can put this solution on YOUR website!
Time for 1 man to do 1 job, m
\n" ); document.write( "time for 1 boy to do 1 job, b\r
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\n" ); document.write( "\n" ); document.write( "R*T=J rule that relates rate, time, amount of job or amount of work\r
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\n" ); document.write( "\n" ); document.write( "\"system%28%282%2Fm%2B5%2Fb%294=1%2C%284%2Fm%2B4%2Fb%293=1%29\"
\n" ); document.write( "Not a linear system, but two equations in two unknown variables.\r
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\n" ); document.write( "\n" ); document.write( "\"system%288b%2B20m=bm%2C12b%2B12m=bm%29\"\r
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\n" ); document.write( "\n" ); document.write( "Use substitution to solve.\r
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\n" ); document.write( "\n" ); document.write( "Pick an equation and solve for a variable.
\n" ); document.write( "\"8b-bm%2B20m=0\"
\n" ); document.write( "\"8b-bm=-20m\"
\n" ); document.write( "\"b%288-m%29=-20m\"
\n" ); document.write( "\"b=-20m%2F%288-m%29\"
\n" ); document.write( "\"b=20m%2F%28m-8%29\"\r
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\n" ); document.write( "\n" ); document.write( "Substitute this formula into the other equation.
\n" ); document.write( "\"12%2820m%2F%28m-8%29%29%2B12m=%2820m%2F%28m-8%29%29m\"\r
\n" ); document.write( "\n" ); document.write( "\"240m%2F%28m-8%29%2B12m=20m%5E2%2F%28m-8%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"240m%2B12m%28m-8%29=20m%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "Divide left and right by 4
\n" ); document.write( "\"60m%2B3m%28m-8%29=5m%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "\"60m%2B3m%5E2-24=5m%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "\"60m-24=2m%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "\"2m%5E2-60m%2B24=0\"\r
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\n" ); document.write( "\n" ); document.write( "Divide left and right by 2
\n" ); document.write( "\"highlight_green%28m%5E2-30m%2B12=0%29\" \r
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\n" ); document.write( "\n" ); document.write( "\"m=%2830%2B-+sqrt%2830%5E2-4%2A12%29%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%2830%2B-+sqrt%28900-48%29%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%2830%2Bsqrt%28852%29%29%2F2\"-----\r
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\n" ); document.write( "\n" ); document.write( "\"m=%2830%2B-+2%2Asqrt%28213%29%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=15%2Bsqrt%28213%29\"--------time for one man ?\r
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