Answer:
b Superscript positive
Step-by-step explanation:
Negative exponents in the denominators can be evaluated by moving the function from the denominator to the numerator and changing the power from negative to the positive.
We have
1/b⁻² = b²
Moving the function with a power from denominator to numerator or from numerator to denominator changes the sign of the power. It is not equal to zero.
This is the property of exponents.