Engineering Board Exam Reviewer · Determinants · medium

A 3×3 matrix A has A=5. Find (2A).

  1. 10
  2. 25
  3. 40
  4. 30

Answer

C. 40

Solution

Multiplying a 3×3 matrix by 2 multiplies each of the three rows by 2, so (2A)=23 A=8(5)=40.

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