document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1062362>Question 1062362</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a pizzeria sells three sizes of pizza: small, medium, and large. the pizzas sell for $9, $10, and $13, respectively. one evening they sold 21 pizzas and received $220. if they sold 1 more medium than large pizzas, how many of each size did they sell?<BR>\n" );
document.write( "Use the Gaussian elimination method with back substitution to solve the given word problem </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #677258 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=677258\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> small=x<BR>\n" );
document.write( "medium=y<BR>\n" );
document.write( "large=z\r<BR>\n" );
document.write( "\n" );
document.write( "x+y+z=21<BR>\n" );
document.write( "9x+10y+13z=220<BR>\n" );
document.write( "y=z+1<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "x+y+z=21<BR>\n" );
document.write( "9x+10y+13z=220<BR>\n" );
document.write( "y-z=1<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "first times -9 and add it to second\r<BR>\n" );
document.write( "\n" );
document.write( "9x+10y+13z=220<BR>\n" );
document.write( "-9x-9y-9z=-189<BR>\n" );
document.write( "y-z=1\r<BR>\n" );
document.write( "\n" );
document.write( "y+4z=31<BR>\n" );
document.write( "y-z=1<BR>\n" );
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document.write( "multiply the third one by -1 and add to second<BR>\n" );
document.write( "y+4z=31<BR>\n" );
document.write( "-y+z=-1<BR>\n" );
document.write( "5z=30<BR>\n" );
document.write( "z=6<BR>\n" );
document.write( "y=z+1<BR>\n" );
document.write( "y=7<BR>\n" );
document.write( "x+y+z=21, x=8<BR>\n" );
document.write( "{8,7,6}<BR>\n" );
document.write( "8*$9=$72<BR>\n" );
document.write( "7*$10=$70<BR>\n" );
document.write( "6*$13=$78<BR>\n" );
document.write( "Total=21 and $220\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );