If $\alpha , \beta$ and $\gamma$ are three consecutive terms of a non-constant G.P. Such that the equations $\alpha x ^ { 2 } + 2 \beta x + \gamma = 0$ and $x ^ { 2 } + x - 1 = 0$ have a common root, then $\alpha ( \beta + \gamma )$ is equal to:\\
(1) $\beta \gamma$\\
(2) $\alpha \beta$\\
(3) $\alpha \gamma$\\
(4) 0