(In reply to re(2): How about .. 2 questions & 1 remark.
I admit that there was some "red herring", intentional , of course.
Both the "maybe", the exponentation and the D2 were part of my planning to disguise the fact that it should be instantly solved: the numbers' sum is 20, reduce the sum by changing 5
into -5. Piece of cake!
Finding that, one is free to shout "Eureka" or feel cheated or explore the task a little more and enjoy the joke.
I have also thought that the 1st solver might come up with one of the more complicated formulas without discovering
the easy one.
Anyway , the purpose was not to avoid a KISS solution,
but make it slighly hidden and less obvious - Columbus' egg....