document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1166854>Question 1166854</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A cellular phone company charges $63.95 per month for a service plan that includes 6 GB of data. In addition to the basic monthly rate, the company charges $7.95 for each additional GB of data over 6 GB. A customer on this plan receives a bill for $119.60. How much data did this customer send and receive during the month? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #791454 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=791454\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the basic charge is 63.95 per month.<BR>\n" );
document.write( "this includes 6 GB of data.<BR>\n" );
document.write( "the company also charges $7.95 for each GB of data over 6 GB.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the customer receives a bill foro $119.60.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "subtract 63.95 from this to get 55.65 in charges for data use over 6 GB.<BR>\n" );
document.write( "divide 55.65 by 7.95 to get 7 GB of data over the free allowance of 6 GB.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "this means the customer used a total of 6 + 7 = 13 GB of data during the month.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if you made a piecewise function to model this, that function would look like this.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "y = 63.95 for x <= 6<BR>\n" );
document.write( "y = 63.95 + 7.95 * (x - 6) for x > 6\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "in this piecewise function, the value of x is the total GB of data used.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "when x = 13, the second piecewise function would be used.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "you would then get y = 63.95 + 7.95 * (13 - 6) = 119.6\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "since you know y, but don't know x, you would assume the second function because y > 63.95 indicates additional usage of data over the minimum.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "the second function becomes.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "119.6 = 63.95 + 7.95 * (x - 6)<BR>\n" );
document.write( "simplify this to get:<BR>\n" );
document.write( "119.6 = 63.95 + 7.95 * x - 47.7<BR>\n" );
document.write( "combine like terms to get:<BR>\n" );
document.write( "119.6 = 7.95 * x + 16.25<BR>\n" );
document.write( "subtract 16.25 from both sides of the equation to get:<BR>\n" );
document.write( "103.35 = 7.95 * x<BR>\n" );
document.write( "solve for x to get:<BR>\n" );
document.write( "x = 103.35 / 7.95 = 13.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "that means that the total number of GB used during the month is 13.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );