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行列式的计算2a113a13-5a121/2a122a213a23-5a221/2a222a313a13-5a321/2a32答案是-3a已知a11a12a13a21a22a23a31a32a33的值为a

题目详情
行列式的计算
2a11 3a13-5a12 1/2a12
2a21 3a23-5a22 1/2a22
2a31 3a13-5a32 1/2a32
答案是-3a
已知a11 a12 a13
a21 a22 a23
a31 a32 a33的值为a
▼优质解答
答案和解析
2a11 3a13 1/2a12   2a11 -5a12 1/2a12
2a21 3a23 1/2a22 + 2a21 -5a22 1/2a22
2a31 3a13 1/2a32   2a31 -5a32 1/2a32
2a11 3a13 1/2a12
2a21 3a23 1/2a22
2a31 3a13 1/2a32
2a11 1/2a12  3a13
2a21 1/2a22  3a23   ×(-1)
2a31 1/2a32  3a13
a11 a12  a13
a21 a22  a23  ×2×1/2×3×(-1)
a31 a32  a13
-3a