SOLUTION: How can you factor and solve ?81x^4-16=0

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Question 378741: How can you factor and solve ?81x^4-16=0
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
By the difference of two squares theorem, this becomes
%289x%5E2+-+4%29%289x%5E2+%2B+4%29+=+0
The first equation, 9x%5E2+-+4+=+0, has solutions at x = 2/3 and x = -2/3. The second equation, 9x%5E2+%2B+4+=+0 has complex roots 2i/3 and -2i/3.