Skip to main contentSkip to solution

If A=[−26−5−1]A = \begin{bmatrix} -2 & 6 \\ -5 & -1 \end{bmatrix} then A−1A^{-1} is :

Solution

✅ Correct Option: 3

∣A∣=(−2)(−1)−(6)(−5)=2+30=32|A| = (-2)(-1) - (6)(-5) = 2 + 30 = 32.

adj(A)=[−1−65−2]\text{adj}(A) = \begin{bmatrix} -1 & -6 \\ 5 & -2 \end{bmatrix}.

A−1=132[−1−65−2]A^{-1} = \frac{1}{32}\begin{bmatrix} -1 & -6 \\ 5 & -2 \end{bmatrix}.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question