document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=66436>Question 66436</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A 12 quart cooling system is filled with a solution that is 10% antifreeze. The desired strength of the solution is 40% antifreeze.  How many quarts of solution need to be drained and replaced with pure antifreeze to reach the desired strength? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #47123 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=47123\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "let x=amount of 10% solution that needs to be drained and replaced with pure antifreeze\r<BR>\n" );
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document.write( "Then 12-x is the amount of 10% antifreeze left after the system was drained\r<BR>\n" );
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document.write( "Now we know that the amount of pure antifreeze left after the system was drained .10(12-x),plus the amount of pure antifreeze added back in (x) equals the amount of pure antifreeze in the final solution (12)(.40).  So our equation to solve is:\r<BR>\n" );
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document.write( ".10(12-x)+x=(12)(.40)  simplifying, we get:\r<BR>\n" );
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document.write( "1.2-.10x+x=4.8  subtract 1.2 from both sides:\r<BR>\n" );
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document.write( ".90x=3.6<BR>\n" );
document.write( "x=4 quarts needs to be drained and replaced by pure antifreeze\r<BR>\n" );
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document.write( "ck\r<BR>\n" );
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document.write( ".10(12-4)+4=4.8<BR>\n" );
document.write( "1.2-.4+4=4.8<BR>\n" );
document.write( ".8+4=4.8<BR>\n" );
document.write( "4.8=4.8\r<BR>\n" );
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document.write( "Hope this helps ----ptaylor\r<BR>\n" );
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document.write( " </SPAN>\n" );
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