Answer:
The answer is 
Step-by-step explanation:
The formula is:

In this case :

To get the simples form notice both 104 and 288 are divisible by 8 and 104/8 = 13 and 288/8 = 36.
Thus 
Try this solution:
Circumference=2*π*radius=2*π*10.25=20.5π (mm).
Do u still have this homework or is it old
X=-16
X/2+6=-2
Subtract 6 from both sides
X/2=-8
Multiply by 2
X=-16