The area (in square units) of the triangle formed by $x+y+1=0$ and the pair of straight lines $x^2-3xy+2y^2=0$ is :

Question

$$\begin {array} {1 1} (1)\;\frac{7}{12} & \quad (2)\;\frac{5}{12} \\ (3)\;\frac{1}{12} & \quad (4)\;\frac{1}{6} \end {array}$$