SOLUTION: I have to completely factor this {{{ (x^2-9)^2 + 8x (x^2-9) }}} thank you!

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Question 970385: I have to completely factor this
+%28x%5E2-9%29%5E2+%2B+8x+%28x%5E2-9%29+
thank you!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let Q+=+x%5E2+-+9

+%28x%5E2-9%29%5E2+%2B+8x+%28x%5E2-9%29+ will turn into +Q%5E2+%2B+8x%2AQ+

Factor out the common term Q to get +Q%5E2+%2B+8x%2AQ+=+Q%2A%28Q+%2B+8x%29+

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Q%2A%28Q+%2B+8x%29

%28x%5E2-9%29%2A%28%28x%5E2-9%29+%2B+8x%29 replace every Q with x^2 - 9

%28x%5E2-9%29%2A%28x%5E2+%2B+8x-9%29 Rearrange terms

%28x-3%29%28x%2B3%29%2A%28x%5E2+%2B+8x+-+9%29 Factor the first x%5E2-9 (difference of squares rule)

%28x-3%29%28x%2B3%29%28x%2B9%29%28x-1%29 Factor x%5E2+%2B+8x+-+9 (note: 9 and -1 multiply to -9 and add to +8)

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So in the end, +%28x%5E2-9%29%5E2+%2B+8x+%28x%5E2-9%29+ factors to %28x-3%29%28x%2B3%29%28x%2B9%29%28x-1%29