Question 1182006
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to express the polynomial in factored form:
r(x) = x4 - 8x2 - 9
r(x) = (x2 + 1)(x2 - 9)
(x) = (x + 1)(x - 1)(x + 3)(x - 3)
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{{{x^4-8x^2-9}}}


-9 and +1 ?
{{{(x^2-9)(x^2+1)}}}


Recognize the Difference Of Squares.  That is the factor containing the {{{-9}}}; not the other factor.


{{{(x-3)(x+3)(x^2+1)}}}