document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=157315>Question 157315</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Pure acid is to be added to a 10% acid solution to obtain 21L of a 40% acid solution. what amount of each should be used? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #115984 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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=115984\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x+.1(21-x)=.4*21<BR>\n" );
document.write( "x+2.1-.1x=8.4<BR>\n" );
document.write( ".9x=8.4-2.1<BR>\n" );
document.write( ".9x=6.3<BR>\n" );
document.write( "x=6.3/.9<BR>\n" );
document.write( "x=7 gallons of pure acid is needed.<BR>\n" );
document.write( "21-7=14 gallons of 10% acid is needed.<BR>\n" );
document.write( "Proof:<BR>\n" );
document.write( "7+.1*14=8.4<BR>\n" );
document.write( "7+1.4=8.4<BR>\n" );
document.write( "8.4=8.4<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );