As the numerator is odd (only odd powers of x), and the denominator is even (only even), the fraction is odd. This is easy to prove.
Consider h(x) = f(x)/g(x)
f(-x) = - f(x) (an odd function)
g(-x) = g(x)
Then, h(-x) = f(-x)/g(-x) = -f(x)/g(x) = -(f(x)/g(x)) = - h(x)
Thus, h(-x) = - h(x)
h is odd.