Question

The value of $\left|\begin{array}{cc}x& x+1\\ x-1& x\end{array}\right|$ is

• A. $0$
• B. $-1$
• C. $1$
• D. $2$

Answer 1

The correct option is C $1$

We have
$\left|\begin{array}{cc}x& x+1\\ x-1& x\end{array}\right|=x\left(x\right)-(x+1)(x-1)=x^2-(x^2-1)=x^2-x^2+1=1$