The set of values of k for which the system of equations

Question:

The set of values of $k$ for which the system of equations $x+y+z=2,2 x+y-z=3,3 x+2 y+k z=4$ has a unique solution, is__________

Solution:

The system of equations $x+y+z=2,2 x+y-z=3$ and $3 x+2 y+k z=4$ has a unique solution.

$\therefore \Delta=\left|\begin{array}{ccc}1 & 1 & 1 \\ 2 & 1 & -1 \\ 3 & 2 & k\end{array}\right| \neq 0$

$\Rightarrow 1(k+2)-1(2 k+3)+1(4-3) \neq 0$

$\Rightarrow k+2-2 k-3+1 \neq 0$

$\Rightarrow k \neq 0$

Thus, the set of values of $k$ for which the given system of equations has a unique solution is $R-\{0\}$.

The set of values of k for which the system of equations + y + z = 2, 2+ y  z = 3, 3+ 2+ kz = 4  has a unique solution, is __R − {0}__.

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