document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=960907>Question 960907</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A cubic polynomial function f has leading coefficient 2 and constant term 7. If f(1)=7 and f(2)=9, what is f(-2)?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #587249 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=587249\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A cubic polynomial function f has leading coefficient 2 and constant term 7. If f(1)=7 and f(2)=9, what is f(-2)? <BR>\n" );
document.write( "------<BR>\n" );
document.write( "f(x) = ax^3 + bx^2 + cx + 7<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Using f(1) = 7 you get: a + b + c + 7 = 7<BR>\n" );
document.write( "Using f(2) = 9 you get: 8a+4b+2c + 7 = 9<BR>\n" );
document.write( "------<BR>\n" );
document.write( "Modify::<BR>\n" );
document.write( "a + b + c = 0<BR>\n" );
document.write( "4a + 2b + c = 1<BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "Subtract to get:<BR>\n" );
document.write( "3a + b = 1<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Since a = 2, 6+b = 1<BR>\n" );
document.write( "b = -5<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve for \"c\"::<BR>\n" );
document.write( "2 -5 + c = 0<BR>\n" );
document.write( "c = 3<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "f(x) = 2x^3 -5x^2 + 3x + 7<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "Ans: f(-2) = -16-20-6+7 = -35<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "------------- </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );