document.write( "Question 1170291: You have 20 gallons of a 45% antifreeze solution. How many gallons of a 57% antifreeze solution needs to be added to make a 51% antifreeze solution? \n" ); document.write( "

Algebra.Com's Answer #795149 by ikleyn(52864) $\"\"$ $\"About$

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document.write( "Let x be the volume of the 57% antifreeze solution to add.\r\n" );
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document.write( "The governing equation is\r\n" );
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document.write( "    0.45*20 + 0.57x = 0.51*(20 + x)\r\n" );
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document.write( "saying that sum of the antifreeze volumes in ingredient is equal to the antifreeze volume in the final mixture.\r\n" );
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document.write( "From the equation\r\n" );
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document.write( "    x =  = 20.\r\n" );
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document.write( "ANSWER.  20 gallons of the 57% antifreeze solution should be added.\r\n" );
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document.write( "CHECK.  I am checking for the concentration  C =  = 0.51 = 51%.\r\n" );
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\n" ); document.write( "\n" ); document.write( "From the other side, the answer is OBVIOUS since 51% is half-way between 45% and 57%.\r
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