if we plug in 1 into this we can find the sum of all the coefficents which is 3^16 and if we plug in -1 into the equation we have the same thing except that the odd terms are negitive becasue -1 to the power of any odd term would make it negitve and even makes it even, and plugging in -1 we get 2^16 now add these values together we get what we want multiplied by 2 so then we divide it all by to giving us the answer: (3^16+2^16)/2 you can do that complicated part on your own .