Question 471418
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9y<sup>6</sup>-27y<sup>4</sup>+18y<sup>2</sup>+6

All the coefficients are evenly divisible by 3, 
so we can take out 3.

3(y<sup>6</sup>-9y<sup>4</sup>+6y<sup>2</sup>+2)

It doesn't factor further.

Edwin</pre>