TRINITY EQUATION WHY IT IS NOT SO FOR QM AND GR.
1/3 APPLE+ 1/3 ORANGE+1/3 ORANGE= 1 APPLE/ORANGE.
In the example you gave the left side makes some sense; you can talk about apples and oranges, and fractions of them. But on the right side you've got an "apple/orange", which isn't a real thing. The same sort of problem crops up when one starts talking about physics.
Every equation describes something. They're like very succinct sentences. Perhaps you could "add them in thirds", but what you get out is very unlikely to make any sense.
For example, here are three sentences I found by googling random words (specifically: wildebeest, summer camp, and water).
-"Gnus belong to the family Bovidea, which includes antelopes, cattle, goats, and other even-toed horned ungulates."
-"And for this round, we've shaken things up a bit, and opened up the promotion to a mix of bands on the 2011 Summer Camp Line Up."
-"We offer information on many aspects of water, along with pictures, data, maps, and an interactive center where you can give opinions and test your water knowledge."
Each says something, and each kinda needs to be used in the right context to make any sense. Combining in thirds you just scramble them even worse:
-"Gnus belong to the family Bovidea and for this round, we've shaken things up a we offer information on many aspects of water, along"
You could wander the world looking for a situation where this sentence makes sense, but there's no reason to expect you'd find it. Moreover, the new sentence itself doesn't makes sense. Despite the fact that all three of the original sentences were grammatically correct (except for starting with "and"), the new sentence has several errors.
The same is true of the equations of QM and GR. They're talking about wildly different stuff.
Let me know if that makes sense or clears anything up, and thanks for asking!
-Physicist