document.write( "Question 1156383: Misty wishes to obtain 85 ounces of a 40% acid solution by combining a 72% acid solution with a 25% acid solution. How much of each solution should misty use? \n" ); document.write( "

Algebra.Com's Answer #779077 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( "Let x = the number of ounces of the stronger (72%)\r\n" );
document.write( "Let y = the number of ounces of the weaker (25%) \r\n" );
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document.write( "We make this chart and fill in what is given:\r\n" );
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document.write( "Acid-H20 solution | Oz. of liquid | % Pure | Oz. of Pure acid | \r\n" );
document.write( "--------------------------------------------------------------- \r\n" );
document.write( "Stronger Strength |      x        |  72%   |                  |\r\n" );
document.write( "Weaker Strength   |      y        |  25%   |                  |\r\n" );
document.write( "------------------|--------------------------------------------\r\n" );
document.write( "Medium Strength   |     85        |  40%   |                  |\r\n" );
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document.write( "Then we take the percentages to get the number of ounces of PURE\r\n" );
document.write( "acid in each solution, of the stronger and weaker before mixing, \r\n" );
document.write( "and of the medium strength after mixing.\r\n" );
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document.write( "Acid-H20 solution | Oz. of liquid | % Pure | Oz. of Pure acid | \r\n" );
document.write( "--------------------------------------------------------------- \r\n" );
document.write( "Stronger Strength |      x        |  72%   |    0.72x         |\r\n" );
document.write( "Weaker Strength   |      y        |  25%   |    0.25y         |\r\n" );
document.write( "------------------|--------------------------------------------\r\n" );
document.write( "Medium Strength   |     85        |  40%   |    0.40(85)      |\r\n" );
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document.write( "Our two equations come from the first and last columns:\r\n" );
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document.write( "Solve the system by substitution or elimination.\r\n" );
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document.write( "As a visual partial check, since the percentage of the final \r\n" );
document.write( "mixture (40%) is nearer to the percentage of the weaker solution\r\n" );
document.write( "(25%) than it is to the stronger solution, we expect that the\r\n" );
document.write( "answer should be so that it takes more of the weaker solution\r\n" );
document.write( "than of the stronger solution. \r\n" );
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document.write( "Edwin

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