document.write( "Question 475280: How many gallons of 90% antifreeze would i add to 70 gallons of 20% antifreeze to get a 80% mixture \n" ); document.write( "
Algebra.Com's Answer #325892 by robertb(5830)\"\" \"About 
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0.20*70 + 0.90*x = 0.80*(70 + x)\r
\n" ); document.write( "\n" ); document.write( "==> 14 + 0.90x = 56 + 0.80x\r
\n" ); document.write( "\n" ); document.write( "==> 0.10x = 42\r
\n" ); document.write( "\n" ); document.write( "==> x = 420 gallons of 90% antifreeze must be added.
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