`AI = ((-3,1,6),(3,-1,0),(4,2,5)) ((1,0,0),(0,1,0),(0,0,1))`

`=((-3+0+0,0+1+0,0+0+6),(3+0+0,0+ -1+0,0+0+0),(4+0+0,0+2+0,0+0+5))`

` =((-3,1,6),(3,-1,0),(4,2,5))`

` =A`

We see that multiplying by the identity matrix does not change the value of the original matrix.

That is,

AI = A

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