Is 2 2 4 a truth?

In other words, 2+2=4 is not necessarily true because it is true in all possible worlds, it is true in all possible worlds because it is set up to be so, by design.

Is math the absolute truth?

Mathematics can never be absolute because relativity is a necessity for this science to exist. Without multiplicity there cannot be any mathematics. Absolute truth cannot be more than one.

Why does 2 plus equal 4?

We know that two plus two equals. Four that's true or is it when proving something in mathematics. We have to start with a series of statements that can be taken as true without argument.