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Question
Find the adjoint of the matrices.
`[(1,-1,2),(2,3,5),(-2,0,1)]`
Solution
`"A" = [(1,-1,2),(2,3,5),(-2,0,1)]`
A11 = 3, A12 = - 12, A13 = 6
A21 = 1, A22 = 5, A23 = 2.
A31 = - 11, A32 = -1, A33 = 5
adj A `= [("A"_11,"A"_21,"A"_21),("A"_12,"A"_22,"A"_32),("A"_13,"A"_23,"A"_33)]^"T"`
`= [(3,-12,6),(1,5,-2),(-11,-1,5)]^"T"`
`= [(3,1,-11),(-12,5,-1),(6,2,5)]`
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