Final answer:
Option a) 7⁻⁵ / 7⁴ is the only expression that is greater than 0 and less than 1, as it simplifies to 1/7⁹, which is a value between 0 and 1.
Step-by-step explanation:
The student asked which of the following expressions is greater than 0 and less than 1: a) 7⁻⁵ / 7⁴ b) 7 c) 4 d) -5. To determine which expression fits this description, we consider the properties of numbers and operations. The only option that falls within this range is a) 7⁻⁵ / 7⁴. To evaluate this, we can subtract the exponents since the bases are the same to get 7⁻⁹, which simplifies to 1/7⁹. Since 7⁹ is a positive number greater than 1, its reciprocal is a positive number less than 1.