Question

13 & 16 & 19 \\ 14 & 17 & 20 \\ 15 & 18 & 21 \end{matrix} \right| =$$

• A. 0
• B. – 39
• C. 96
• D. 57

Answer 1

Answer: (A)

0

Answer 2

Applying $C_{3} \rightarrow C_{3} - C_{2}$and $C_{2} \rightarrow C_{2} - C_{1}$, we get

$\left| \begin{matrix} 13 & 3 & 3 \\ 14 & 3 & 3 \\ 15 & 3 & 3 \end{matrix} \right| = 0$ , $\{\because C_{2} \equiv C_{3}\}$.