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# FP1 Matrices question watch

1. Why is that in this question (part c) http://i.imgur.com/1o1uiPl.png
AB = C is changed to B=CA^(-1)

while in this question http://i.imgur.com/bH4ZwNV.png
MC=A is changed to C=M^(-1)A

When should the inverse be on the left or right.

Thanks
2. This is a triple duplicate before anybody posts and tries to help the OP.
3. The key piece of understanding in these questions is the non-commutativioty of Matrix multiplication and hence this

"AB = C is changed to B=CA^(-1)" would normally be B=A^(-1)C after premultiplying both sides by A^(-1).

As inidcated by Zacken, you have multiposted.Please dont.

From a glance at the question, you need to understand as well that applying first A and then B would be BA, and not AB.

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