## The problem

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Hello

why is (a2)-1 turn into a-2? if a2-1 is the rule?

then it would be a1

## Answer provided by our tutors

It is because 2*(-1) = -2.

The following rule is applied:

(a^b)^c = a^(bc)

so

(a^2)^(-1) = a^(2*(-1)) = a^(-2)