I would say B .
They are not like terms because they are not all the same
-18-(-12)=-6
Since there is two negative sign, it turns into positive meaning the -12 becomes positive 12 and the -18 stays same. So -18+12=-6 because 18 is bigger than 12 and it's negative so the final answer should be negative.
Hint: when you see two negative sign just turn them into plus sign.
Answer:
C. teacher-student
Step-by-step explanation:
the pattern is girl, boy, girl boy, and teacher and student don't have a gender connection
