Given a finite Group G, with A, B subgroups prove the order of AB
4
$\begingroup$
How do you prove:
Given a finite group $G$, with $A,B$ subgroups then $$|AB|=\frac{|A||B|}{|A \cap B|}.$$
abstract-algebragroup-theoryfinite-groups
asked 2011-11-03
user id:18766
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See [this post](http://math.stackexchange.com/questions/168942/order-of-a-product-of-subgroups) and other questions [linked there](http://math.stackexchange.com/questions/linked/168942) – 2016-07-19
2 Answers
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