document.write( "Question 1136822: how many liters of a 12% alcohol solution must be added to 15 liters of a 5% alcohol solution to get a mixture that is 8% alcohol? \n" ); document.write( "

Algebra.Com's Answer #754649 by rothauserc(4718) $\"\"$ $\"About$

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let x be the number of liters needed to add to the 12% solution
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\n" ); document.write( "we have three relations, the third relation is the mixture
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\n" ); document.write( "1) x * 0.12 = 0.12x
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\n" ); document.write( "2) 15 * 0.05 = 0.75
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\n" ); document.write( "3) (x+15) * 0.08 = 0.08(x+15)
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\n" ); document.write( "0.12x +0.75 = 0.08(x+15)
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\n" ); document.write( "0.12x +0.75 = 0.08x +1.20
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\n" ); document.write( "0.04x = 0.45
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\n" ); document.write( "x = 11.25
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\n" ); document.write( "11.25 liters of the 12% solution is necessary
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\n" ); document.write( "check answer
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\n" ); document.write( "0.12(11.25) +0.75 = 0.08(11.25) +1.20
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\n" ); document.write( "1.35 +0.75 = 0.90 +1.20
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\n" ); document.write( "2.1 = 2.1
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\n" ); document.write( "also
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\n" ); document.write( "(11.25 + 15) * 0.08 = 2.1
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\n" ); document.write( "answer checks
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