Answer: 
<u>Step-by-step explanation:</u>

NOTE: The sign between 4x and 7 is missing in the question you posted. I assumed it was 4x + 7 in order to solve the equation.
20096m.
Since the radius is 80, the formula is x²×3.14.
80²=6400
6400×3.14=20096
m is the unit
Answer: 20096 meters
Answer: me + u is us
Step-by-step explanation:
Answer:
11x2+6x
Step-by-step explanation: