Binomial Theorem

If the co-efficient of \(x^9\) in \({\left( {\alpha {x^3} + {1 \over {\beta x}}} \right)^{11}}\) and the co-efficient of \(x^{-9}\) in \({\left( {\alpha x - {1 \over {\beta {x^3}}}} \right)^{11}}\) are equal, then \((\alpha\beta)^2\) is equal to ___________.