document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=391816>Question 391816</A>: <I><SPAN STYLE=\"word-break: break-all;\"> several books are on sale at a bookstore. some of these books cost 3 dollars , while other cost 5 dollars. one day last week, 80 of these books were sold. the total amount of sales was 300 dollars. how many of each type was sold?<BR>\n" );
document.write( "1. write the equations that would solve the system<BR>\n" );
document.write( "2show and explain how you solved the problem<BR>\n" );
document.write( "3 how do you know you have the correct solution\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 #277976 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=277976\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> several books are on sale at a bookstore. some of these books cost 3 dollars , while other cost 5 dollars. one day last week, 80 of these books were sold. the total amount of sales was 300 dollars. how many of each type was sold?<BR>\n" );
document.write( "1. write the equations that would solve the system<BR>\n" );
document.write( "Quantity Equation: t + f = 80 books<BR>\n" );
document.write( "Value Equation::  3t +5f = 300 dollars<BR>\n" );
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document.write( "2show and explain how you solved the problem<BR>\n" );
document.write( "Multiply thru the Quantity Eq. by 3 to get:<BR>\n" );
document.write( "3t+3f = 3*80<BR>\n" );
document.write( "Subtract that from the Value Eq. to get:<BR>\n" );
document.write( "2f = 60<BR>\n" );
document.write( "f = 30 (# of 5 dollar books sold)<BR>\n" );
document.write( "Since t + f = 80, t = 50 (# of 3 dollar books sold)<BR>\n" );
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document.write( "3 how do you know you have the correct solution<BR>\n" );
document.write( "Check the Value:<BR>\n" );
document.write( "5*30+50*3 = 150+150 = $300<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. \r<BR>\n" );
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