document.write( "Question 1163316: How many gallons of a 80% antifreeze solution must be mixed with 70 gallons of
\n" ); document.write( "30% antifreeze to get a mixture that is 70% antifreeze? \n" ); document.write( "
Algebra.Com's Answer #787379 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "80% antifreeze solution is 80% alcohol and 20% other stuff.\r\n" );
document.write( "30% antifreeze solution is 30% alcohol and 70% other stuff.\r\n" );
document.write( "70% antifreeze solution is 70% alcohol and 30% other stuff.\r\n" );
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document.write( "how many| percent | how many  |\r\n" );
document.write( "gallons | alcohol |  gallons  |\r\n" );
document.write( "  of    |  as a   |    of     |\r\n" );
document.write( "solution| decimal |  alcohol  |\r\n" );
document.write( "--------|---------|-----------|\r\n" );
document.write( "   x    |   0.8   | 0.8x      |\r\n" );
document.write( "  70    |   0.3   | 0.3(70)   |  \r\n" );
document.write( "--------|---------|-----------| \r\n" );
document.write( "  x+70  |   0.7   | 0.7(x+70) |\r\n" );
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document.write( "The equation comes from the last column\r\n" );
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document.write( "0.8x + 0.3(70) = 0.7(x+70)\r\n" );
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document.write( "Solve that.  The answer is more than 200 and less than 300 gallons.\r\n" );
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document.write( "That's a big answer, but we should expect that because 30% is pretty \r\n" );
document.write( "weak compared to 70%, so it should take a lot.\r\n" );
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document.write( "Edwin
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