If a and b are integers when is 1/ab positive?

Question

Please help me, I don't know what to do.

Answer 1

In order for 1/ab to be positive meaning it is greater the zero the denominator must be positive since the numerator is positive.

Since both a and b are in the denominator to get a positive number a&b both have to be positive or they both have to be negative.

Did I explain clearly?