document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1113181>Question 1113181</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The function 4.3x+y=198 models the number of land-line phone customers, in millions, x years after 2000. The function y=19.8x+98 models the number of cell phone customers, in millions, x years after 2000. \r<BR>\n" );
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document.write( "a. Use these models to determine the year, rounded to nearest year, when the number of cell phone and landline customers is the same.\r<BR>\n" );
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document.write( "b. according to the models, how many customers were there for each type of phone customer for the year determined in part a. (rounded to the nearest ten million)? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #728634 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=728634\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> put both functions into the same form.\r<BR>\n" );
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document.write( "i chose slope intercept form.\r<BR>\n" );
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document.write( "the function 4.3x + y = 198 becomes y = -4.3x + 198\r<BR>\n" );
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document.write( "the function y = 19.8x + 98 is already in slope intercept form.\r<BR>\n" );
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document.write( "you have 2 equations that need to be solved simultaneously.\r<BR>\n" );
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document.write( "they are:\r<BR>\n" );
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document.write( "y = -4.3x + 198<BR>\n" );
document.write( "y = 19.8x + 98\r<BR>\n" );
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document.write( "to eliminate the y variable, subtract the second equation from the first to get:\r<BR>\n" );
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document.write( "0 = -24.1x + 100\r<BR>\n" );
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document.write( "add 24.1x to both sides of the equation to get:\r<BR>\n" );
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document.write( "24.1x = 100\r<BR>\n" );
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document.write( "solve for x to get:\r<BR>\n" );
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document.write( "x = 100 / 24.1 = 4.149377593\r<BR>\n" );
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document.write( "this means the number of landline customers will be equal to the number of cell phone customer sometime in the 4th year after 2000.\r<BR>\n" );
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document.write( "that would be 2004.\r<BR>\n" );
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document.write( "you can graph this equation.\r<BR>\n" );
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document.write( "it would look like this:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/033101.jpg\" alt=\"$$$\">\r<BR>\n" );
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document.write( "if you want x to represent the actual year, then you need to shift the graph over to the right by 2000.\r<BR>\n" );
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document.write( "that graph would look like this.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/033102.jpg\" alt=\"$$$\">\r<BR>\n" );
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document.write( "your questions and answers to them are shown below:\r<BR>\n" );
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document.write( "a. Use these models to determine the year, rounded to nearest year, when the number of cell phone and landline customers is the same.\r<BR>\n" );
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document.write( "that would be sometime in 2004.\r<BR>\n" );
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document.write( "b. according to the models, how many customers were there for each type of phone customer for the year determined in part a. (rounded to the nearest ten million)?\r<BR>\n" );
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document.write( "when they were equal, the number of customers was 180.1576763 million.\r<BR>\n" );
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document.write( "round this to the nearest 10 million and it becomes 180 million.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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