Answer
-13608
Work Step by Step
We know from the Binomial Theorem (page 693) that we can expand the given expression without multiplying it out. Doing this, we obtain:
$$x^{16}-24x^{14}+252x^{12}-1512x^{10}+5670x^8-13608x^6+20412x^4-17496x^2+6561$$
Thus, the given coefficient is -13608.