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-42
Explanation
the determinant of a 2 X 2 matrix is given by:
[tex]\begin{bmatrix}{a} & {b} \\ {c} & {d}\end{bmatrix}=ad-bc[/tex]so, the determinant of the matrix
[tex]\begin{bmatrix}{-6} & {0} \\ {4} & {7}\end{bmatrix}[/tex]would be
[tex]\begin{gathered} \begin{bmatrix}{-6} & {0} \\ {4} & {7}\end{bmatrix}=\left(-6*7\right)-\left(4*0\right)=-42-0=-42 \\ so \\ det\left(\right?\begin{bmatrix}{-6} & {0} \\ {4} & {7}\end{bmatrix}=-42 \\ \end{gathered}[/tex]therefore, the answer is
-42
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