А+б=?

The symbols "а" and "б" represent variables that could stand for any numbers, letters, or symbols within a given mathematical, linguistic, or programming context. If you meant them to represent numbers in an addition context, then "а+б" would simply equal the sum of the two variables "а" and "б". Without specific values being assigned to these variables, we cannot provide a numerical answer. If you have specific values for "а" and "б", please provide them, and I can calculate the sum for you. If they are not numbers but rather placeholders in a different context, please provide more details.