If A = \(\begin{bmatrix}13 & 5\\3 & 1 \end{bmatrix}\), then what can be said about 8\( { A }^{ -1 } \)?
Answer & explanation
Correct answer: option 2
\( { A }^{ -1 } \) =\(\frac{adj A}{|A|}\)
But |A| = -2
So, \( { A }^{ -1 } \) =\(\frac{adj A}{-2}\)
8 \( { A }^{ -1 } \) = 8 \(\frac{adj A}{-2}\)
=- 4 (adj A)