The system of linear equations:

x + y + z = 2

2x + y – z = 3

3x + 2y + kz = 4

The matrix equation corresponding to the above system is

=

Let A =

|A| = = 1(k+2) -1(2k+3) +1(4-3) = k+2-2k-3+1 = -k

For the system to have a unique solution , it is necessary that |A| 0

-k 0

Thus,