document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=969612>Question 969612</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find all real and complex roots. \r<BR>\n" );
document.write( "\n" );
document.write( "x^4-9x^2+20=0\r<BR>\n" );
document.write( "\n" );
document.write( "-The solution set is { }.<BR>\n" );
document.write( "(Use a comma to separate answers as needed. Type an exact answer, using radicals as needed. Type complex answers in the form a + bi.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #592450 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=592450\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I would factor into <BR>\n" );
document.write( "(x^2-5)(X^2-4)=0.  It is just like factoring a quadratic, only you end up with quadratic roots.\r<BR>\n" );
document.write( "\n" );
document.write( "x^2-5=0   x^2=5   x=plus sqrt(5) and minus sqrt (5)\r<BR>\n" );
document.write( "\n" );
document.write( "x^2-4=0<BR>\n" );
document.write( "(x+2)(x-2)=0  Difference of squares.\r<BR>\n" );
document.write( "\n" );
document.write( "x=2,-2\r<BR>\n" );
document.write( "\n" );
document.write( "The four roots are -sqrt (5), -2, 2, and sqrt (5)\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28300%2C200%2C-3%2C3%2C-5%2C30%2Cx%5E4-9x%5E2%2B20%29 ALIGN=MIDDLE  ALT=\"+graph%28300%2C200%2C-3%2C3%2C-5%2C30%2Cx%5E4-9x%5E2%2B20%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );