document.write( "Question 383116: a 14 litre solution is 25% antifreeze and 75% water, how much antifreeze should i add to make the solution 30% antifreeze? \n" ); document.write( "
Algebra.Com's Answer #271359 by ptaylor(2198)\"\" \"About 
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Let x=amount of antifreeze that needs to be added
\n" ); document.write( "Now we know that the amount of water before the mixture takes place is equal to the amount of water after the mixture takes place, so:
\n" ); document.write( "0.75*14=0.70(14+x)
\n" ); document.write( "10.5=9.8+0.70x subtract 9.8 from each side
\n" ); document.write( "10.5-9.8=0.70x
\n" ); document.write( "0.7=0.70x
\n" ); document.write( "x=1 gal --------------amount of pure antifreeze needed
\n" ); document.write( "Another way: The amount of pure antifreeze also remains the same before and after the mixture takes place, so:
\n" ); document.write( "0.25*14+x=0.30(14+x)
\n" ); document.write( "3.5+x=4.2+0.30x
\n" ); document.write( "x-0.30x=4.2-3.5
\n" ); document.write( "0.70x=0.7
\n" ); document.write( "x=1 gal\r
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor\r
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