MHT CET20227 Aug 2022Evening ShiftMathematicsMatricesActual

If A= [ array ccc 1 & -1 & 1 2 & -1 & 0 3 & 3 & -4 array ] , adj A= [ array ccc 4 & -1 & 1 8 & -7 & a 9 & -6 & b array ] , then

Options

Aa=2, b=-1
Ba=2, b=1
Ca=-2, b=1
Da=1, b=-2

Correct answer

B. a=2, b=1

Step-by-step solution

aligned & A= [ array ccc 1 & -1 & 1 2 & -1 & 0 3 & 3 & -4 array ], adj A= [ array lll 4 & -1 & 1 8 & -7 & a 9 & -6 & b array ] & now, A adj A= [ array ccc 5 & 0 & 1-a+b 0 & 5 & 2-a 0 & 0 & 3+3 a-4 b array ]=|A| . I & 1-a+b=0 and 2-a=0 & a=2 and b=1 aligned

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