How do you FOIL $(9 - x^{2}) (9 - x^{2})$ $(9-x^2)(9-x^2)$ ?

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Answer 1 · 2015-07-20T14:32:40

$x^{4} - 18 x^{2} + 81$ $x^4-18x^2+81$

$(9 - x^{2}) (9 - x^{2}) = 81 - 9 x^{2} - 9 x^{2} + x^{4} = x^{4} - 18 x^{2} + 81$ $(9-x^2)(9-x^2)=81-9x^2-9x^2+x^4=x^4-18x^2+81$

How do you FOIL (9-x^2)(9-x^2)(9−x2)(9−x2)(9-x^2)(9-x^2)?