Solve the given equation if we know that x=2\displaystyle {x}=-{2} is a solution of the equation.

x6+6x5+9x44x312x2=0\displaystyle {x}^{{6}}+{6}{x}^{{5}}+{9}{x}^{{4}}-{4}{x}^{{3}}-{12}{x}^{{2}}={0}