Answer:
-18b^8.
Step-by-step explanation:
To simplify an expression, we combine the elements that are similar (look the same).
So, it we have -20b^8 + 2b^8, we see that there are 2 terms with b^8. We need to simplify them.
So, we have -20b^8 + 2b^8, that addition leaves -18b^8.
-18b^8 cannot be simplified more.
