Solve the equation: $\displaystyle {p}^{{2}}+{3}{p}-{108}={0}$

Answer: $\displaystyle {p}=$

Write your answers as a list of integers or simplified fractions, with your answers separated by (a) comma(s). For example, if you get $\displaystyle {4}$ and $\displaystyle -\frac{{2}}{{3}}$ as your answers, then enter 4,-2/3 in the box.