document.write( "Question 336359: how many gallons of pure alcohol should be mixed with 20 gallons of 15% alcohol solution to obtain a mixture that is 25% alcohol? \n" ); document.write( "
Algebra.Com's Answer #241367 by Fombitz(32388)\"\" \"About 
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Let A be the amount of 100% alcohol added.
\n" ); document.write( "\"100A%2B15%2820%29=25%28A%2B15%29\"
\n" ); document.write( "\"100A%2B300=25A%2B375\"
\n" ); document.write( "\"75A=75\"
\n" ); document.write( "\"A=1\"
\n" ); document.write( "One gallon of pure alcohol needs to be added.
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