document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=527956>Question 527956</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sorry, this was a section that I was not able to cover due to schedule changes. Thank You!<BR>\n" );
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document.write( "     The problem: Rhonda mixes some 35% acid solution with some 70% acid solution to make 100mL of a 42% acid solution. How much of the 35% acid solution did she use?\r<BR>\n" );
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document.write( "      Again, Thank You for  your time,<BR>\n" );
document.write( "           A student </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #349097 by </B><A HREF=/tutors/aboutme.mpl?userid=oberobic><B>oberobic(2304)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oberobic><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=349097\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> With mixture problems, you need to determine how much 'pure' stuff you have or need.<BR>\n" );
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document.write( "She needs to make 100 mL @ 42% = 42 mL of pure acid.<BR>\n" );
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document.write( "The two amounts will total 100 mL, so she adds<BR>\n" );
document.write( "x mL of 35% acid with<BR>\n" );
document.write( "100-x mL of 70% acid<BR>\n" );
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document.write( ".35x + .7(100-x) = .42(100)<BR>\n" );
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document.write( "multiply both sides by 100 to eliminate decimals<BR>\n" );
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document.write( "35x + 70(100-x) = 42(100)<BR>\n" );
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document.write( "35x + 7000 -70x = 4200<BR>\n" );
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document.write( "-35x = -2800<BR>\n" );
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document.write( "x = -2800/-35 = 80 mL of 35% acid <BR>\n" );
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document.write( "100-x = 20 mL of 70% acid<BR>\n" );
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document.write( "check how much pure acid you have to be sure<BR>\n" );
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document.write( ".35*80 = 28 mL<BR>\n" );
document.write( ".70*20 = 14 mL<BR>\n" );
document.write( "28+14 = 42 mL<BR>\n" );
document.write( "correct<BR>\n" );
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document.write( "Answer:  Mix 80 mL of 35% acid + 20 mL of 70% acid to produce 100 mL of 42% acid.<BR>\n" );
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document.write( "Done. </SPAN>\n" );
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