document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=475083>Question 475083</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am a little confused on this problem and not sure where to start. Help would be greatly apprieciated.\r<BR>\n" );
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document.write( "The polynomial 0.0014x^3-0.07x^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. In which year between 1979 and 1990 was natural gas consumption about 21.7 trillion cubic feet? \r<BR>\n" );
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document.write( "Thanks Abby </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #325776 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=325776\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I'm not sure I understand this either.<BR>\n" );
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document.write( "The polynomial 0.0014x^3-0.07x^2+1.5x+11 models natural gas consumption in trillions of cubic feet,<BR>\n" );
document.write( " where x=0 corresponds to 1960, x=1 to 1961, and so on.<BR>\n" );
document.write( " In which year between 1979 and 1990 was natural gas consumption about 21.7 trillion cubic feet? <BR>\n" );
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document.write( "Write the given equation to equal 21.7 <BR>\n" );
document.write( ".0014x^3 - .07x^2 + 1.5x + 11 = 21.7<BR>\n" );
document.write( "subtract 21.7 from both sides<BR>\n" );
document.write( ".0014x^3 - .07x^2 + 1.5x + 11 - 21.7 = 0<BR>\n" );
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document.write( ".0014x^3 - .07x^2 + 1.5x - 10.7 = 0<BR>\n" );
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document.write( "Plot the equation:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-10%2C+50%2C+-30%2C+30%2C+.0014x%5E3+-+.07x%5E2+%2B+1.5x+-+10.7+%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-10%2C+50%2C+-30%2C+30%2C+.0014x%5E3+-+.07x%5E2+%2B+1.5x+-+10.7+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "You can see x ~ 13 yrs which would be 1973, This amt will not occur between 1979 and 1990 <BR>\n" );
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