If im not wrong. The answer would be 11.6 because you need to substract b-a which gives you 5.8. Then you multiply that by 2.
You're basically using the supplement angle to find the missing number.
Answer:
12
Step-by-step explanation:
If f(x) = 5 - x
Then f(-7) = 5 - (-7)
f(-7) = 5 + 7
f(-7) = 12