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根据行列式的性质,将行列式的第二列乘以2,第三列乘以-2,再将第二列加到第三列,最后用第一列的数去乘以第二列和第三列后的代数和,即可得出答案。D=$\left |\begin{matrix} {a}_{11}& {a}_{12}& {a}_{13}\\ {a}_{21}& {a}_{22}& {a}_{23}\\ {a}_{31}& {a}_{32}& {a}_{33}\end{matrix} |=\dfrac {1}{2} \right.$${D}_{1}=$ $\left |\begin{matrix} 2{a}_{11}& {a}_{13}\\ 2{a}_{21}& {a}_{23}\\ 2{a}_{31}& {a}_{33}\end{matrix} | \right.$ $\left \begin{matrix} {a}_{11}-2{a}_{12}\\ {a}_{21}-2{a}_{22}\\ {a}_{31}-2{a}_{32}\end{matrix} | \right.$ =2$\left |\begin{matrix} {a}_{11}-2{a}_{12}& {a}_{13}\\ {a}_{21}-2{a}_{22}& {a}_{23}\\ {a}_{31}-2{a}_{32}& {a}_{33}\end{matrix} | \right.$=2$\left |\begin{matrix} {a}_{11}& {a}_{13}\\ {a}_{21}& {a}_{23}\\ {a}_{31}& {a}_{33}\end{matrix} | \right.$=2D故答案为A |
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