Answer:
10.21 feet.
Step-by-step explanation:
circumference of circle with diameter d is given by 
where r is the radius of the circle.
_____________________________
given
diameter = 6 1/2 = 13/2 feet
\thus, circumference of circle is calculated as following

Thus, circumference of given circle is 10.21 feet.
Answer: X = 0
Let me know if it’s correct
Combine like-terms
-2.1x and 4.9x = 2.8x
3.7 and 5 = 8.7
2.8x + 8.7 is your final answer.