Let \( \alpha, \beta, \gamma \) be the real roots of the equation, \( x^3 + ax^2 + bx + c = 0 \), \( (a,b,c \in \mathbb{R} \) and \( a,b \ne 0) \). If the system of equations (in \( u, v, w \)) given by \( \alpha u + \beta v + \gamma w = 0 \); \( \beta u + \gamma v + \alpha w = 0 \); \( \gamma u + \alpha v + \beta w = 0 \) has non-trivial solution, then value of \( \dfrac{\alpha^2}{b} \) is: