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Matrix A = 1 2 3 1 1 5 2 4 7 then the value of a 31 A 31 + a 32 A 32 + a 33 A 33 is

Options

  1. A1
  2. B13
  3. C- 1
  4. D- 13

Correct answer

C. - 1

Step-by-step solution

We know that a 31 A 31 + a 32 A 32 + a 33 A 33 = | A | Now | A | = 1 ( 7 − 20 ) − 2 ( 7 − 10 ) + 3 ( 4 − 2 ) = − 13 + 6 + 6 = − 1

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