What are the like terms ?

-8 and -2

12x and -x

12x and 2x

-12x and -2x

Like terms are terms that have the same variable raised to the same power.

In the given list of terms:
-8 and -2 are like terms because they have no variables.
12x and -x are not like terms because they have different variables (x and -x).
12x and 2x are like terms because they both have the variable x raised to the first power.
-12x and -2x are like terms because they both have the variable x raised to the first power, and they have the same coefficient (-12 and -2).