Question

The value of the determinant $\left| \begin{matrix}

• 1 & 1 & 1 \ 1 & - 1 & 1 \ 1 & 1 & - 1 \end{matrix} \right|$is equal to.

• A. – 4
• B. 0
• C. 1
• D. 4

Answer 1

Answer: (D)

4

Answer 2

Apply $R_{1} \rightarrow R_{1} + R_{2}$ and then expand along $R_{1}$.