SOLUTION: Show that the sum of all real zeros (including their multiplicity)of the polynomial f(x)=x^4+x^3-17x^2-21x+36 is equal to -1

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Question 777316: Show that the sum of all real zeros (including their multiplicity)of the polynomial f(x)=x^4+x^3-17x^2-21x+36 is equal to -1
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Show that the sum of all real zeros (including their multiplicity)of the polynomial f(x)=x^4+x^3-17x^2-21x+36 is equal to -1
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The sum of the coefficients is zero, so x = 1 is a zero.
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1)....1....1....-17....-21....36
......1....2....-15....-36...|..0
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x = 4 is a zero of x^3+2x^2-15x-36
4)....1....2....-15....-36
......1....6.....9....|..0
x = -3 with multiplicity two are zeroes of x^2+6x+9
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Sum: 1 +4 + -3 + -3 = -1
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Cheers,
Stan H.