Question

The number of solutions of the system of equations $2x+y-z=7$ , $x-3y+2z=1$ and $x+4y-3z=5$ is

• A. 3
• B. 2
• C. 1
• D. 0

Answer 1

Answer: (D)

$\Delta =\left|\begin{array}{ccc}2& 1& -1\\ 1& -3& 2\\ 1& 4& -3\end{array}\right|$
$=2(9-8)-1(-3-2)-1(4+3)$
$=7-7=0$
Hence, number of solutions is zero.