Question

(x 4 - 81) (x - 3) . write answers in descending power of x. (division)

Answer 1

x^3+3x^2+9x+27

Explanation:

`(x^4-81)/(x-3)=((x^2-9)(x^2+9))/(x-3)=((x-3)(x+3)(x^2+9))/((x-3))\\\\=(x+3)(x^2+9)=x^3+3x^2+9x+27`

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The factoring of the difference of squares is used (twice):

a² -b² = (a -b)(a +b)