Answer:
-1.17 volts
Explanation:
The difference between "a" and "b" generally means "a-b". Here, the difference between the potentials is ...
-0.41 V - 0.76 V = -1.17 V
_____
Sometimes, when we talk about the difference, we mean the positive difference. If that is what is intended here, it is 1.17 volts.