# A Matrix problem by hobart pao

Algebra Level 4

If $$A=\begin{pmatrix} 2 & 6 & 6 & 2 \\ 2 & 7 & 3 & 6 \\ 1 & 5 & 0 & 1 \\ 3 & 7 & 0 & 7 \end{pmatrix}$$, what is the determinant of $$A^{-1}$$? Express the answer in the form $$-\dfrac{a}{b}$$ in lowest terms, and find the sum $$a+b$$.

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