A = `[[5, 0, 2],[0, 3, 0],[2, 0, 1]]`. The inverse of A is
`[[1, 0, -2],[0, 1/3, 0],[-2, 0, 5]]`
`[[5, 0, 2],[0, -1/3, 0],[2, 0, 1]]`
`[[1/5, 0, 1/2],[0, 1/3, 0],[1/2, 0, 1]]`
`[[1/5, 0, -1/2],[0, 1/3, 0],[-1/2, 0, 1]]`
how to find inverse of a 3*3 matrix