document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=34369>Question 34369</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A university bookstore recently sold a wirebound graph-paper notebook for $2.50, and a college-ruled notebook for $2.30. At the start of spring semester, a combination of 50 of these notebooks were sold for a total of $118.60. How many of each type were sold? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #20690 by </B><A HREF=/tutors/aboutme.mpl?userid=usyim88hk><B>usyim88hk(158)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=usyim88hk><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=20690\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We can use Substitution to work on this problem:<BR>\n" );
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document.write( "Let x be the number of wirebound graph-paper notebook<BR>\n" );
document.write( "Let y be the number of college-ruled notebook<BR>\n" );
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document.write( "So we now have an equation<BR>\n" );
document.write( "x + y = 50<BR>\n" );
document.write( "since the numbers of this two kinds of notebook add up to 50<BR>\n" );
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document.write( "now we can make another equation<BR>\n" );
document.write( "2.5x + 2.3y = 118.6<BR>\n" );
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document.write( "2.5x means the earning of the sold wirebound graph-paper notebooks<BR>\n" );
document.write( "2.3y means the earning of the sold college-ruled notebooks<BR>\n" );
document.write( "and they add up to 118.6<BR>\n" );
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document.write( "Now we can solve for x<BR>\n" );
document.write( "x + y = 50<BR>\n" );
document.write( "x = 50 - y<BR>\n" );
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document.write( "Now substitute x into the other equation<BR>\n" );
document.write( "2.5x + 2.3y = 118.6<BR>\n" );
document.write( "2.5 (50 - y) + 2.3y = 118.6<BR>\n" );
document.write( "(x is equal to 50 - y so the x in the second equation become 50-y)<BR>\n" );
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document.write( "Now solve for y<BR>\n" );
document.write( "2.5 (50 - y) + 2.3y = 118.6<BR>\n" );
document.write( "125 - 2.5y + 2.3y = 118.6<BR>\n" );
document.write( "125 - 0.2y = 118.6<BR>\n" );
document.write( "125 = 118.6 + 0.2y<BR>\n" );
document.write( "6.4 = 0.2y<BR>\n" );
document.write( "y = 32<BR>\n" );
document.write( "So the total numebr of sold college-ruled notebooks is 32, while the total number of sold wirebound graph-paper notebooks is 50 - 32 = 18 </SPAN>\n" );
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