document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=321649>Question 321649</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Dorothy bought two computers, one desktop and one laptop. Before finance charges, the laptop cost $1000 more than the desktop. Dorothy paid for the computers using two different financing plans. For the desktop the interest rate was 5% per year, and for the laptop it was 9.5% per year. The total finance charges for one year were $638.75. How much did the desktop computer cost before finance charges?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #230326 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=230326\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let D = cost of the desktop<BR>\n" );
document.write( "Let L = cost of the laptop<BR>\n" );
document.write( "L = D + 1000\r<BR>\n" );
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document.write( "Total interest rate paid for one year was 638.75\r<BR>\n" );
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document.write( "That interest rate was composed of D * .05 + L * .095\r<BR>\n" );
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document.write( "Formula is .05*D + .095*L = 638.75\r<BR>\n" );
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document.write( "Since L = D + 1000, this formula becomes:\r<BR>\n" );
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document.write( ".05*D + .095*(D + 1000) = 638.75\r<BR>\n" );
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document.write( "Simplify this to get:\r<BR>\n" );
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document.write( ".05*D + .095*D + .095*1000 = 638.75\r<BR>\n" );
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document.write( "Combine like terms and simplify further to get:\r<BR>\n" );
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document.write( ".145*D + 95 = 638.75\r<BR>\n" );
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document.write( "Subtract 9 from both sides of this equation to get:\r<BR>\n" );
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document.write( ".145*D = 543.75.\r<BR>\n" );
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document.write( "Divide both sides by .145 to get:\r<BR>\n" );
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document.write( "D = 3750<BR>\n" );
document.write( "L = D + 1000 = 4750\r<BR>\n" );
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document.write( ".05 * D + .95 * L = 638.75\r<BR>\n" );
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document.write( ".05 * 3750 + .095 * 4750 = 638.75 confirming the values are good.\r<BR>\n" );
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document.write( "Your answer is that the price of the desktop computer before finance charges is $3750.00\r<BR>\n" );
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