Answer:
It might be A I might be wrong.
Step-by-step explanation:
Hi!
-9f + 19 - 1 + f is actually -8f + 18.
To do this we add like terms, -9f and f; and 19 and -1
-9f + f is -8f
19 - 1 is 18
Therefore your answer is -8f + 18
