If I see a problem where we have 1/p + 1/q, then in solving the problem, can't I convert those fractions to be the same as p to the minus 1 and q to the minus one? Also, if I have DS data that P=5 and q=7,then can't I say P to the minue one = 1/5 and q to the minus one = 1/7??

It would be a problem solving method.

If it's wrong, please explain why. Thank you.

If you have (1/p + 1/q), that can be rewritten as p^(-1) + q^(-1).

If you have p=5, then p^(-1) = 1/5.
If you have q=7, then q^(-1) = 1/7.

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