In the final part of the ratio test, divide the numerator and the denominator by n and take n to infinity which takes all of the constants to zero. The bottom simplifies to k*k for k times. The numerator simplifies to 1^(k) or 1.
Within the absolute value bars, disregarding the what you have are th degree polynomials in the numerator and denominator in , so we know the limit as is the ratio of the leading coefficients, which is:
And so the limit of the entire expression is: