Answers

2016-04-12T10:56:05+05:30
Well it is cramer's rule:
A=  \left[\begin{array}{ccc}1&2&3\\4&5&6\\7&8&9\end{array}\right]
=1(5*9 - 8*6)-2(4*9 - 7*6)+3(4*8 - 7*5)
= 45-48 - 2(36-42)+3(32-35)
= -3 -2(-6)+3(-3)
= -3+12-9
= 0

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