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If A is a symmetric matrix and B is a skew-symmetric matrix such that A + B = ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − 1 5 3 2 , then AB is equal to :

1. ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − − 4 1 2 4
2. ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − − − 4 1 2 4
3. ⎥ ⎦ ⎤ ⎢ ⎣ ⎡− 4 1 2 4
4. ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − − − 4 1 2 4

Correct answer: ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − − − 4 1 2 4

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