if A is an invertible matrix of order 3 and |A|=5 the find the value of |adjA|

Consider,
A-1=adjAAA×A-1=A×adjAAI=A×adjAA

Since, A is invertible

I×A=A×adjAI×A=A×adjA

A3=A×adjA [Since, A is an invertible matrix of order 3]

adjA=A2adjA=52=25

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