Suppose a, b are nonzero integers such that two roots of x^{3}+a x^{2}+b x+9 a coincide, and all three roots are integers. Find |a b|.
Suppose a, b are nonzero integers such that two roots of x^{3}+a x^{2}+b x+9 a coincide, and all three roots are integers. Find |a b|.