Question

If $\left|\begin{array}{ccc}1& 1& 0\\ 2& 0& 3\\ 5& -6& x\end{array}\right|=29,$ then $x$ is

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

Answer: (B)

Given, that, $\left|\begin{array}{ccc}1& 1& 0\\ 2& 0& 3\\ 5& -6& x\end{array}\right|=29$
$\Rightarrow$ $1(0+18)-1(2x-15)=29$
$\Rightarrow$ $18-2x+15=29$
$\Rightarrow$ $2x=4$
$\Rightarrow$ $x=2$