Given, A = 2-3-47 compute A-1 and show that 2

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189.

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190.

Given, A = 2-3-47 compute A-1 and show that 2A- = 9I-A


A  = 2-3-47C11 = (-1)1+1 (7)  = 7,C12 = (-1)1+2 (-4) = 4C21 = (-1)2+1 (-3) = 3C22 = (-1)2+2 2= 2Adj A = 7432'  = 7342|A| = 2 x 7 - (-3) x (-4) = 14 -12  0 A-1 = 1|A| adj A = 127342 = 7/23/221L.H.S = 2A-1 = 2 7/23/221  = 7342R.H.S =  9 I - A  = 9 1001 - 2-3-47 = 9009 - 2-3-47 = 9-2349-7 = 7342 L.H.S = R.H.SHence, verified that 2A-1 = 9I - A


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