Engineering Board Exam Reviewer · Determinants · medium

Evaluate vmatrix2&-1&3\1&4&-2\3&0&1 vmatrix.

  1. -35
  2. -21
  3. 21
  4. 51

Answer

B. -21

Solution

Expand along the first row: 2 vmatrix4&-2\0&1 vmatrix-(-1) vmatrix1&-2\3&1 vmatrix+3 vmatrix1&4\3&0 vmatrix=2(4)+1(7)+3(-12)=8+7-36=-21.

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