The graphs of the linear equations 4x - 2y = 10 and 4x + ky = 2 intersect at a point (a, 4). The value of k is equal to:

$$\eqalign{ & \,\,\,\,4x - 2y = 10 \cr & \,\,\,\,4x + ky = 2 \cr & \underline {\, - \,\,\,\,\,\, - \,\,\,\,\,\,\,\,\, - \,\,\,\,} \cr & \left( { - k - 2} \right)y = 8 \cr & {\text{The quardinate of }}y{\text{ is}} = 4 \cr & \left( { - k - 2} \right) \times 4 = 8 \cr & - k - 2 = 2 \cr & k = - 4 \cr} $$