document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=712065>Question 712065</A>: <I><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "During one month, a homeowner used 200 units of electricity and 130 units of gas for a total cost of $81.60. The next month, 220 units of electricity and 200 units of gas were used for a total cost of $96.60. Find the cost per unit of gas. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #437758 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley79><B>checkley79(3341)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley79><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=437758\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 200X+130Y=81.60 MULTIPLY BY -1.1 & ADD.<BR>\n" );
document.write( "220X+200Y=96.60<BR>\n" );
document.write( "-220X-143Y=-89.76<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "57Y=6.84<BR>\n" );
document.write( "Y=6.84/57<BR>\n" );
document.write( "Y=$.12 PER UNIT OF GAS.<BR>\n" );
document.write( "200X+130*.12=81.60<BR>\n" );
document.write( "200X+15.6=81.60<BR>\n" );
document.write( "200X=81.60-15.6<BR>\n" );
document.write( "200X=66<BR>\n" );
document.write( "C=66/200<BR>\n" );
document.write( "X=$.33  PER UNIT OF ELECTRICITY.<BR>\n" );
document.write( "PROOF:<BR>\n" );
document.write( "220*.33+200*.12=96.60<BR>\n" );
document.write( "72.60+24=96.60<BR>\n" );
document.write( "96.60=96.60 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );