The value of $\lambda$ such that $\lambda x^2-10 xy+12 y^2+5x-16y-3=0$ represents a pair of straight lines, is

$\begin {array} {1 1} (1)\;1 & \quad (2)\;-1 \\ (3)\;2 & \quad (4)\;-2 \end {array}$

(3) 2
answered Nov 7, 2013 by