document.write( "Question 746137: how many liters each of a 15% acid solution and a 25% acid solution must be used to produce 80 liters of a 20% acid solution \n" ); document.write( "
Algebra.Com's Answer #454181 by josgarithmetic(39617)\"\" \"About 
You can put this solution on YOUR website!
The quick guess is 40 liters of each, given numbers like those.\r
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\n" ); document.write( "\n" ); document.write( "The solving process:\r
\n" ); document.write( "\n" ); document.write( "u and v for volumes to use
\n" ); document.write( "\"%2815u%2B25v%29%2F80=20\" and \"u%2Bv=80\"\r
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\n" ); document.write( "\n" ); document.write( "\"15u%2B25v=1600\"
\n" ); document.write( "\"3u%2B5v=320\"\r
\n" ); document.write( "\n" ); document.write( "working from volume sum equation, \"v=80-u\", so substitute.
\n" ); document.write( "\"3u%2B5%2880-u%29=320\"
\n" ); document.write( "\"3u%2B400-5u=320\"
\n" ); document.write( "\"-2u=320-400\"
\n" ); document.write( "\"2u=400-320\"
\n" ); document.write( "\"2u=80\"
\n" ); document.write( "\"highlight%28u=40%29\", ..... See what I mean?
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