12ab + 8ab + 5ab

is it 25ab

yes.

Yes it is.

To simplify the expression 12ab + 8ab + 5ab, you can combine the like terms, which have the same variables raised to the same powers. In this case, all the terms have the variable "ab" in common.

To combine the coefficients, which are the numbers in front of the variables, you add them together.

So, adding 12ab + 8ab + 5ab, you get:

12ab + 8ab + 5ab = (12 + 8 + 5)ab = 25ab

Therefore, the simplified expression is 25ab.