Is the 100 J of electric potential energy actually greater than -100 J of electric potential energy?
They have the same magnitude but the sign is the indication of the work done (energy needed) to bring a +1C of charge from an infinite distance to points with those two potentials. The definition is that Positive work is needed to bring +1C to the +110J point (pushing up a hill) but negative work is done (i.e. energy is got out) then the +1C is brought to the -100J point (sliding down to a valley).
Given the way the question is phrased and the units that are used, I would interpret it to be about the potential energy of two configurations of the same system. One with a potential energy 100 J more than an arbitrary reference potential and one with 100 J less than the arbitrary reference.
Clearly, one has 200 J less electrical potential energy than the other.
Sounds fair and I can't find fault with that. The question could either require a totally theoretical answer or something practical. We would need the OP to give us a bit of help with the context. What does he actually want to know and why?
Can @rpthomps help us to help him more, please?
Or it might have the syntax of a question but be devoid of semantics.
Thanks guys for the response! The question, was answered, as intended by @sophiecentaur but @jbriggs444 brought up another way of thinking about it.
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