$A$ is a square matrix of order 2 with $|A| = 6$. What is $|-3A|$?

Explanation

1. 01

   $-3A$ multiplies each of the 2 rows of $A$ by $-3$, and each row brings out one factor $-3$.

2. 02

   $|-3A| = (-3)^{2}|A| = 9 \times 6 = 54$.