Question

Solve for $x$:

$\left|\begin{array}{ccc}1-x& 2& 3\\ 0& x& 0\\ 0& 0& x\end{array}\right|=0$

• A. $1,0,0$
• B. $1,1,0$
• C. $1,1,1$
• D. $0,0,0$

Answer 1

Answer: (A)

$1,0,0$

Given,

$\left|\begin{array}{ccc}1-x& 2& 3\\ 0& x& 0\\ 0& 0& x\end{array}\right|=0$

or, $(1-x)x^2=0$ [ Expanding with respect to row one]

or, $x=1,0,0$.