document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1154243>Question 1154243</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The table lists a readings for three years. <BR>\n" );
document.write( "​(a) If the quadratic relationship between the carbon dioxide concentration C and the year t is expressed as Upper C equals at squared plus bt plus c​, where t equals 0 corresponds to​ 1962, use a system of linear equations to determine the constants​ a, b, and​ c, and give the equation.<BR>\n" );
document.write( "​(b) Predict the year when the amount of carbon dioxide in the atmosphere will double from its 1962 level.<BR>\n" );
document.write( "Year<BR>\n" );
document.write( "1962<BR>\n" );
document.write( "1992<BR>\n" );
document.write( "2022\r<BR>\n" );
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document.write( "CO2<BR>\n" );
document.write( "318<BR>\n" );
document.write( "341<BR>\n" );
document.write( "371<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #776655 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=776655\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> ---------<BR>\n" );
document.write( "expressed as Upper C equals at squared plus bt plus c​,<BR>\n" );
document.write( "---------\r<BR>\n" );
document.write( "<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=C=at%5E2%2Bbt%2Bc ALIGN=MIDDLE  ALT=\"C=at%5E2%2Bbt%2Bc\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
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document.write( "\n" );
document.write( "-----------<BR>\n" );
document.write( "Year<BR>\n" );
document.write( "1962<BR>\n" );
document.write( "1992<BR>\n" );
document.write( "2022<BR>\n" );
document.write( "CO2<BR>\n" );
document.write( "318<BR>\n" );
document.write( "341<BR>\n" );
document.write( "371<BR>\n" );
document.write( "-----------\r<BR>\n" );
document.write( "\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "Year     t           <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=CO%5B2%5D ALIGN=MIDDLE  ALT=\"CO%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > Levels\r\n" );
document.write( "1962      0               318\r\n" );
document.write( "1992     30               341\r\n" );
document.write( "2022     60               371       - this has not happened yet.\r\n" );
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document.write( "Variable t was an adjustment from the given year data for easier computation for the steps and the model.\r\n" );
document.write( "</PRE> </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );