document.write( "Question 88624: Solve x^3 - 4x^2 - 2x + 20 = 0 over the set of complex numbers. \n" ); document.write( "
Algebra.Com's Answer #64431 by Nate(3500)\"\" \"About 
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x^3 - 4x^2 - 2x + 20 = 0
\n" ); document.write( "Descartes Rule of Signs:
\n" ); document.write( "Pos: 2 . 0
\n" ); document.write( "Neg: 1 . 1
\n" ); document.write( "Img: 0 . 2
\n" ); document.write( "We know that there is a negative root for sure...
\n" ); document.write( "Possible roots:
\n" ); document.write( "a = 1,2,4,5,10,20
\n" ); document.write( "b = 1
\n" ); document.write( "+- a/b
\n" ); document.write( "+-1, +-2, +-4, +-5, +-10, +-20 are the \"real\" choices
\n" ); document.write( "Synthetic Division (or any division you know at this point):
\n" ); document.write( "..-2..|........1.......-4.......-2.......20
\n" ); document.write( "....................1.......-6......10........0
\n" ); document.write( "(x + 2)(x^2 - 6x + 10) = 0
\n" ); document.write( "x^2 - 6x + 10 = 0 and x + 2 = 0
\n" ); document.write( "x^2 - 6x = -10
\n" ); document.write( "(x - 3)^2 = -1
\n" ); document.write( "x = 3 +- i and x = -2
\n" ); document.write( "\"graph%28300%2C300%2C-5%2C5%2C-2%2C16%2Cx%5E3+-+4x%5E2+-+2x+%2B+20%29\" \n" ); document.write( "
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