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Question
If A = `[[1,-2,3],[0,-1,4],[-2,2,1]]` ,find (A')-1
Solution
`A=[[1,-2,3],[0,-1,4],[-2,2,1]]`
`=>A'=[[1,0,-2],[-2,-1,2],[3,4,1]]`
Now
`|A'|=|[1,0,-2],[-2,-1,2],[3,4,1]|=1(-1-8)-0(-2-6)-2(-8+3)=-9+10=1ne 0`
`adjA'=[[-9,-8,-2],[8,7,2],[-5,-4,-1]]`
`therefore (A')^-1="adjA'"/|A'|`
`=>(A')^-1=[[-9,-8,-2],[8,7,2],[-5,-4,-1]]`
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