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One element of A^-1 from its cofactor

This type of question, asked 3 times: 13 Apr 2026 S2, 15 Apr 2026 S2, 16 Apr 2026 S2. All 3 questions below, oldest first.

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  1. Question 1

    13 Apr 2026 S2

    65
    The element in 1st row and 2nd column of the inverse of the matrix [13−2−30−5250]\begin{bmatrix} 1 & 3 & -2 \\ -3 & 0 & -5 \\ 2 & 5 & 0 \end{bmatrix} is ...

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  2. Question 2

    15 Apr 2026 S2

    68
    The element in the third row and the second column in the inverse matrix of a matrix [133313334]\begin{bmatrix} 1 & 3 & 3 \\ 3 & 1 & 3 \\ 3 & 3 & 4 \end{bmatrix} is

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  3. Question 3

    16 Apr 2026 S2

    64
    If A=[aij]3×3A = [a_{ij}]_{3 \times 3} is a matrix such that aij=∣2i−5j∣a_{ij} = |2i - 5j|, where ∣⋅∣|\cdot| denotes the modulus function, then the element in the 2nd2^{nd} row and 3rd3^{rd} column of A−1A^{-1} is ...

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