document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=750912>Question 750912</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me find the answer! <BR>\n" );
document.write( "suppose you have 80 ml of a solution that is 60% acid and 40% water. how much acid do you need to add to make a solution that is 75% acid.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #456874 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=456874\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> you have 80 ml of a solution that is 60% acid\r<BR>\n" );
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document.write( "so you have 80*0.6 = 48 mL of pure acid\r<BR>\n" );
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document.write( "Let x = amount of pure acid\r<BR>\n" );
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document.write( "If you add x mL of pure acid to 48 mL of pure acid, then you'll have 48+x mL of pure acid total. This is out of 80 + x mL of new total solution.\r<BR>\n" );
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document.write( "This ratio (48+x)/(80+x) must be equal to 0.75 since we want this new percentage to be 75%, so\r<BR>\n" );
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document.write( "(48+x)/(80+x) = 0.75\r<BR>\n" );
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document.write( "now solve for x\r<BR>\n" );
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document.write( "(48+x)/(80+x) = 0.75\r<BR>\n" );
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document.write( "48+x = 0.75(80+x)\r<BR>\n" );
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document.write( "48+x = 60+0.75x\r<BR>\n" );
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document.write( "x = 60+0.75x - 48\r<BR>\n" );
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document.write( "x-0.75x = 60 - 48\r<BR>\n" );
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document.write( "0.25x = 12\r<BR>\n" );
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document.write( "x = 12/0.25\r<BR>\n" );
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document.write( "x = 48\r<BR>\n" );
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document.write( "So you need to add 48 mL of pure acid.\r<BR>\n" );
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