document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=448128>Question 448128</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The charge for electricity is 3 cents per unit for lighting and 1/2 cents per unit for heating.A man's bill for a quarter should have been $8. by mistakes his lighting was charged at 1/2cents per unit and his heating at 3 cents per unit. the amount of the bi1l was $13. use any matrix method to find how many units of electricity he used altogether </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #308454 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=308454\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The charge for electricity is 3 cents per unit for lighting and 1/2 cents per unit for heating.<BR>\n" );
document.write( "--------------------------<BR>\n" );
document.write( "A man's bill for a quarter should have been $8. <BR>\n" );
document.write( "-----------------------------------------------------<BR>\n" );
document.write( "By mistakes his lighting was charged at 1/2 cents per unit and his heating at 3 cents per unit. the amount of the bi1l was $13. <BR>\n" );
document.write( "-----------------------------------------------------<BR>\n" );
document.write( "Use any matrix method to find how many units of electricity he used altogether<BR>\n" );
document.write( "===============================================<BR>\n" );
document.write( "Equations:<BR>\n" );
document.write( "Proper charges: 3L + (1/2)H = 800 cents<BR>\n" );
document.write( "Wrong Charges: (1/2)L+ 3H = 1300 cents<BR>\n" );
document.write( "-----------------------------------------------<BR>\n" );
document.write( "Multiply thru 1st by by 2.<BR>\n" );
document.write( "Multiply thru 2nd by 12<BR>\n" );
document.write( "----<BR>\n" );
document.write( "6L + H = 1600<BR>\n" );
document.write( "6L = 18H = 12*1300<BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "Subtract and solve for \"H\":<BR>\n" );
document.write( "17H = 14000<BR>\n" );
document.write( "H = 823.53<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Solve for L:<BR>\n" );
document.write( "3L + (1/2)H = 800<BR>\n" );
document.write( "3L + 411.76 = 800<BR>\n" );
document.write( "3L = 388.24<BR>\n" );
document.write( "L = 129.4``<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Total # of units = 823.53 + 129.41 = 952.94<BR>\n" );
document.write( "=============================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );