document.write( "Question 537453: How much pure acid should be mixed with 5 gallons of a 70% acid solution in order to get a 90% acid solution? \n" ); document.write( "
Algebra.Com's Answer #352876 by mananth(16946)\"\" \"About 
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--------percent ---------------- quantity
\n" ); document.write( "Acid solution 70 ---------------- 5 gallons
\n" ); document.write( "Pure acid 100 ---------------- x gallons
\n" ); document.write( "Mixture 90 ---------------- 5 + x gallons
\n" ); document.write( "
\n" ); document.write( "70 * 5 + 100 x = 90 ( 5 + x )
\n" ); document.write( "350 + 100 x = 450 + 90 x
\n" ); document.write( "100 x + -90 x = 450 - -350
\n" ); document.write( "10 x = 100
\n" ); document.write( "/ 10
\n" ); document.write( "x = 10
\n" ); document.write( " 10 gallons of Pure acid \r
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