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If `A=[[1,2,2],[2,1,-2],[a,2,b]]` is a matrix satisfying the equation `text(A)A^T =9I`, where `I` is 3x3 identity matrix, then the ordered pair (a,b) is equal to
A. |
(2, -1) |
B. |
(-2, 1) |
C. |
(2, 1) |
D. |
(-2, -1) |
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