Math!!! can't solve this...
posted by hmmm .
If the expression (x^2+2x−1)^8 is completely expanded, what is the sum of the coefficients of the terms with even powers of x?

256
Not sure what's the point of using such a high power. Tedious, but doesn't provide any real insight. 
@Steve r u sure of ur answer?

Steve is correct, the sum is 256
I let Wolfram do all the drudgery
http://www.wolframalpha.com/input/?i=expand+%28x%5E2%2B2x−1%29%5E8
Agree with Steve, this question is simply a test of patience. 
Thanks, Reiny. I used wolfram also :)