document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=400956>Question 400956</A>: <I><SPAN STYLE=\"word-break: break-all;\"> how much pure acid should be added to 18 L of 30% acid to increase the concentration of 50% acid? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #283744 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=283744\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> how much pure acid should be added to 18 L of 30% acid to increase the concentration of 50% acid?<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "acid + acid = acid<BR>\n" );
document.write( "0.30*18 + 1*x = 0.50(18+x)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Multiply thru by 100 to get:<BR>\n" );
document.write( "30*18 + 100x = 50*18 + 50x<BR>\n" );
document.write( "50x = 20*18<BR>\n" );
document.write( "x = (2/5)(18)<BR>\n" );
document.write( "x = 36/5 = 7 1/5 L (amt of pure acid needed)<BR>\n" );
document.write( "==============<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );