It would be the second one if you follow PEMDAS
Answer:

Step-by-step explanation:
we know that
---> by addition angle postulate
we have
----> given problem
----> given problem
substitute in the expression above

Divide by 2 both sides

f(b) = -1/6b + 8. Is the function rule if you want. further explanation just ask.
Answer:
I believe the answer ur looking for is 3 (D)
Step-by-step explanation: