document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=181866>Question 181866</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Alexandra purchases two doughnuts and three cookies at a doughnut shop and is charged $3.30. Briana purchases five doughnuts and two cookies at the same shop for $4.95. All the doughnuts have the same price and all the cookies have the same price. Find the cost of one doughnut and find the cost of one cookie.\r<BR>\n" );
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document.write( "Please show work. \r<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 #136485 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=136485\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "Let the cost of one donut be <i>d</i> and the cost of one cookie be <i>c</i>.\r<BR>\n" );
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document.write( "Then A's purchase is described by:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \text{          }\math 2d + 3c = 330 \text{ cents}\">\r<BR>\n" );
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document.write( "And B's purchase is described by:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \text{          }\math 5d + 2c = 495 \text{ cents}\">\r<BR>\n" );
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document.write( "Note the change from expressing the cost in dollars to expressing the cost in cents -- that gets rid of the decimal fractions and makes things neater.\r<BR>\n" );
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document.write( "Solve the system of two equations for the values of <i>d</i> and <i>c</i> remembering that the answers will come out in cents which you can convert back to decimal parts of a dollar if you wish.\r<BR>\n" );
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document.write( "Hint:  Solve by the elimination method.  Multiply the first equation by 2 and the second by -3 to eliminate the <i>c</i> variable.\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi} + 1 = 0\"><BR>\n" );
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