Simple,
12+-15-6+9
First, -15-6= -21
leaving you...
12+-21+9
21+-21=0
Thus, your answer is, 0.
Choice 1.
Explanation:
You can see the line decreasing so that means the slope should be negative. (every time the line decreases the slope is negative, when it increases the slope is positive)
The number(s) might be -5.5 or -6. I believe the answer might've been -6 but I'm not so sure about that. Please let me know.
HOPE THIS HELPS YOU..... IF NOT I'M SO SORRY
To get circumference you must multiply the diameter by pi(the equivalent to 3.14. If you multiply 4.25 by 3.14 you would get 13.345. If you need to round up it would be 13.3 inches.