20. \( x^{3}+8 x^{2}-9 x-72 \)

Did you know that the equation you're looking at can be thought of as a fun little puzzle waiting to be solved? Polynomial equations like this one can often be tackled using the Rational Root Theorem. This theorem suggests that potential rational roots can be found among the factors of the constant term and the leading coefficient. In your case, you might want to test out simple values such as \( x = 2 \) or \( x = -3 \) to see if they work as solutions! Another method to approach cubic equations like this is synthetic division. Once you’ve found a root, you can break down the cubic polynomial into a product of a linear factor and a quadratic. This makes it much easier to solve for the remaining roots with either factoring or the quadratic formula. Remember, patience and a little bit of trial and error can lead you to the solution!