Question

If \( A = \begin{bmatrix} 2 & 1 5 & 3 \end{bmatrix} \), then \( A^{-1} = \) ____.

• A. \( \begin{bmatrix} 3 & -1 -5 & 2 \end{bmatrix} \)
• B. \( \begin{bmatrix} 3 & 1 -5 & 2 \end{bmatrix} \)
• C. \( \begin{bmatrix} 3 & 1 5 & 2 \end{bmatrix} \)
• D. None

Hint:

When the determinant $|A| = 1$, the inverse of the matrix is simply its adjoint. Always check the determinant first; if it's 1, you can write the answer by inspection!

Answer 1

The Correct Option is A