document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=997435>Question 997435</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A group of 18 people ordered soup and sandwiches for lunch. Each person in the group had either one soup or one sandwich. The sandwiches cost $7.75 each and the soups cost $4.50 each. If the total cost of all 18 lunches was 113.50, bow many sandwiches were ordered? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #615519 by </B><A HREF=/tutors/aboutme.mpl?userid=addingup><B>addingup(3677)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=addingup><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=addingup><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=615519\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let's call soup x and sandwich y:<BR>\n" );
document.write( "x+y= 18 Subtract y from both sides and we get:<BR>\n" );
document.write( "x= 18-y<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "4.50x= 7.75y= 113.50 Let's in this formula substitute the value of x per above:<BR>\n" );
document.write( "4.50(18-y)+7.75y= 113.50<BR>\n" );
document.write( "81-4.50y+7.75y= 113.50 Subtract 81 on both sides and add y on left<BR>\n" );
document.write( "3.25y= 32.5 Divide both sides by 3.25<BR>\n" );
document.write( "y= 10 They ordered 10 sandwiches<BR>\n" );
document.write( "----------------------------------<BR>\n" );
document.write( "Proof:<BR>\n" );
document.write( "10*7.75= 77.5<BR>\n" );
document.write( "18-10=8soups*4.50= 36<BR>\n" );
document.write( "77.5+36=113.50 We have the correct answer<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );