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GUJCET · Maths · Determinants

If \(A=\left[\begin{array}{rrr}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right], 10 B=\left[\begin{array}{rrr}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\) and \(B\) is inverse of matrix \(A\) then, \(\alpha\) is equal to ____________ .

  1. A 3
  2. B 9
  3. C 5
  4. D 10
Verified Solution

Answer & Solution

Correct Answer

(C) 5

Step-by-step Solution

Detailed explanation

Given \(B\) is the inverse of \(A\), then \(AB = I\). Therefore, \(A(10B) = 10I\).