document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=385312>Question 385312</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A book cost $15 if bought online and $22.50 if bought at the store. The bookstore sold 250 books and took in $4995. How many books were bought online and how many were bought in the store? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #272624 by </B><A HREF=/tutors/aboutme.mpl?userid=texttutoring><B>texttutoring(324)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=texttutoring><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=texttutoring><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=272624\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You have two variables, so you need to make two equations.\r<BR>\n" );
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document.write( "Let x = number of books bought online<BR>\n" );
document.write( "Let y = number of books bought in store\r<BR>\n" );
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document.write( "There were 250 books sold in total:\r<BR>\n" );
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document.write( "x+y = 250\r<BR>\n" );
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document.write( "Their sales totaled $4995:\r<BR>\n" );
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document.write( "15x + 22.50y = 4995\r<BR>\n" );
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document.write( "Use elimination or substitution with the two equations to solve for x and y. I will use elimination, by multiplying the first equation by 15, then subtracting.\r<BR>\n" );
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document.write( "15x + 22.50y = 4995<BR>\n" );
document.write( "15x + 15y = 3750<BR>\n" );
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document.write( "0 + 7.50y = 1245\r<BR>\n" );
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document.write( "y = 1245/7.50<BR>\n" );
document.write( "y= 166\r<BR>\n" );
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document.write( "Now find x:\r<BR>\n" );
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document.write( "x+y=250<BR>\n" );
document.write( "x+166=250<BR>\n" );
document.write( "x=250-166<BR>\n" );
document.write( "x=84\r<BR>\n" );
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document.write( "So there were 84 books sold online, and 166 sold in the store. Hope this helps! Let me know if you need any more help.<BR>\n" );
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