SOLUTION: Factor each of the following completely. x^4-81y^4

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Question 789207: Factor each of the following completely.
x^4-81y^4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Apply the difference of squares rule (twice) to get

x^4-81y^4

(x^2)^2-(9y^2)^2

(x^2-9y^2)(x^2+9y^2)

(x^2-(3y)^2)(x^2+9y^2)

(x-3y)(x+3y)(x^2+9y^2)