Explanation:
f(x) = (x+5)^2 = x^2+10x+25 = x^2+10x^1+25x^0
The exponents for that last expression are 2, 1, 0
The mix of even and odd exponents in the standard form means f(x) is neither even nor odd. We would need to have all exponents even to have f(x) even, or have all exponents odd to have f(x) be odd.