Question

If A = \(\begin{bmatrix} 1 &0& 1 \\[0.3em] 0 &1 &2 \\[0.3em] 0 & 0 & 4 \end{bmatrix}\) then show that |3A| = 27 |A|

Answer 1

from (1) and (2)

|3A| = 27|A|