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MHT CET202120 Sep 2021Evening ShiftMathematicsMatricesActual

If A⁻¹= [ array cc 2 & -3 -1 & 2 array ] and B⁻¹= [ array cc 1 & 0 -3 & 1 array ] , then (A B)⁻¹=

Options

  1. A[ array cc 2 & 7 3 & -1 array ]
  2. B[ array cc 2 & -7 -3 & 11 array ]
  3. C[ array cc 2 & -3 -7 & 11 array ]
  4. D[ array cc 2 & 3 7 & -11 array ]

Correct answer

C. [ array cc 2 & -3 -7 & 11 array ]

Step-by-step solution

aligned & ( AB )⁻¹= B ⁻¹ ~A ⁻¹ & = [ array cc 1 & 0 -3 & 1 array ] [ array cc 2 & -3 -1 & 2 array ] & = [ array cc 2+0 & -3+0 -6-1 & 9+2 array ]= [ array cc 2 & -3 -7 & 11 array ] aligned

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