We check the 2nd degree polynomial if we can factorize it. It is not factorizable and it has only imaginary roots. so we keep it as it is.
We write +16 on RHS because the coefficient of (highest degree term) v^3 in numerator is -16 and in denominator - 1 * +1 = -1, and hence -16 v^3/- v^3.
Since 4-v is first degree polynomial, write A in the numerator. B x +C in the second fraction because the other factor is a second degree polynomial.
Solve the above for A, B and C.
You get answer