Question

$\left|\begin{array}{cc}x& 4\\ 2& 1\end{array}\right|=2$
Find the value of x?

• A. 11
• B. 10
• C. 5
• D. 9

Answer 1

The correct option is B 10

$\left|\begin{array}{cc}x& 4\\ 2& 1\end{array}\right|=2$

$\Rightarrow 1\times x-8=2$
$\Rightarrow x-8=2$
$\Rightarrow x=8+2$
$\Rightarrow x=10$
$\Rightarrow x=\frac{10}{1}$
$\Rightarrow x=10$