document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=460032>Question 460032</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello. Referred to me by Minka.\r<BR>\n" );
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document.write( "The polynomial 0.0013x^3 - 0.075x^2 + 1.5x + 11 models natural gas consumption in trillions of cubic feet, where x=0 corresponds to 1960, x=1 to 1961, and so on.<BR>\n" );
document.write( "In which year between 1970 and 1990 was natural gas consumption about 23.1 trillion cubic feet?\r<BR>\n" );
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document.write( "Truly greatful to whom replies.<BR>\n" );
document.write( "Samantha\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #315525 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=315525\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+%2B+11=23.1 ALIGN=MIDDLE  ALT=\"0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+%2B+11=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+=23.1-11 ALIGN=MIDDLE  ALT=\"0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+=23.1-11\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+=12.1 ALIGN=MIDDLE  ALT=\"0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+=12.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+-12.1=0 ALIGN=MIDDLE  ALT=\"0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+-12.1=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "let's see the graph first:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+600%2C+600%2C+-20%2C+50%2C+-15%2C+30%2C+0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+-12.1%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "from the graph you see that only <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=29 ALIGN=MIDDLE  ALT=\"x=29\"   DISABLED_style= \"max-width:90%; height:auto;\" > is a real solution that might work\r<BR>\n" );
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document.write( "let's check it:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+%2B+11=23.1 ALIGN=MIDDLE  ALT=\"0.0013x%5E3+-+0.075x%5E2+%2B+1.5x+%2B+11=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013%2829%29%5E3+-+0.075%2829%29%5E2+%2B+1.5%2A29+%2B+11=23.1 ALIGN=MIDDLE  ALT=\"0.0013%2829%29%5E3+-+0.075%2829%29%5E2+%2B+1.5%2A29+%2B+11=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.0013%2824389%29+-+0.075%28841%29+%2B+1.5%2A29+%2B+11=23.1 ALIGN=MIDDLE  ALT=\"0.0013%2824389%29+-+0.075%28841%29+%2B+1.5%2A29+%2B+11=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=31.7057+-63.075+%2B+43.5+%2B+11=23.1 ALIGN=MIDDLE  ALT=\"31.7057+-63.075+%2B+43.5+%2B+11=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=86.2057+-63.075+=23.1 ALIGN=MIDDLE  ALT=\"86.2057+-63.075+=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=23.1307+=23.1 ALIGN=MIDDLE  ALT=\"23.1307+=23.1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "if <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=0+ ALIGN=MIDDLE  ALT=\"x=0+\"   DISABLED_style= \"max-width:90%; height:auto;\" >corresponds to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1960 ALIGN=MIDDLE  ALT=\"1960\"   DISABLED_style= \"max-width:90%; height:auto;\" > then <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=29 ALIGN=MIDDLE  ALT=\"x=29\"   DISABLED_style= \"max-width:90%; height:auto;\" > corresponds to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1989 ALIGN=MIDDLE  ALT=\"1989\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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