document.write( "Question 1025825: a lab tech needs to make a 126-liter batch of a 20% acid solution, how can the lab tech combine a batch od an acid solution that is oure acid with another that is 10% to get desired concentration \n" ); document.write( "
Algebra.Com's Answer #641137 by josmiceli(19441)\"\" \"About 
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Let \"+a+\" = liters of pure acid needed
\n" ); document.write( "Let \"+b+\" = liters of 10% solution needed
\n" ); document.write( "-----------------
\n" ); document.write( "(1) \"+a+%2B+b+=+126+\"
\n" ); document.write( "(2) \"+%28+a+%2B+.1b+%29+%2F+126+=+.2+\"
\n" ); document.write( "-------------------------
\n" ); document.write( "(2) \"+a+%2B+.1b+=+25.2+\"
\n" ); document.write( "(2) \"+10a+%2B+b+=+252+\"
\n" ); document.write( "Subtract (1) from (2)
\n" ); document.write( "(2) \"+10a+%2B+b+=+252+\"
\n" ); document.write( "(1) \"+-a+-+b+=+-126+\"
\n" ); document.write( "---------------------
\n" ); document.write( "\"+9a+=+126+\"
\n" ); document.write( "\"+a+=+14+\"
\n" ); document.write( "and
\n" ); document.write( "\"+a+%2B+b+=+126+\"
\n" ); document.write( "\"+b+=+126+-+14+\"
\n" ); document.write( "\"+b+=+112+\"
\n" ); document.write( "------------------
\n" ); document.write( "14 liters of pure acid are needed
\n" ); document.write( "112 liters of 10% solution are needed
\n" ); document.write( "---------------------------------
\n" ); document.write( "check:
\n" ); document.write( "(2) \"+%28+a+%2B+.1b+%29+%2F+126+=+.2+\"
\n" ); document.write( "(2) \"+%28+14+%2B+.1%2A112+%29+%2F+126+=+.2+\"
\n" ); document.write( "(2) \"+%28+14+%2B+11.2+%29+%2F+126+=+.2+\"
\n" ); document.write( "(2) \"+25.2+=+.2%2A126+\"
\n" ); document.write( "(2) \"+25.2+=+25.2+\"
\n" ); document.write( "OK
\n" ); document.write( "
\n" );