Answer:
Step-by-step explanation:

Answer:
f(r) = 2πr
Step-by-step explanation:
You know the formula for circumference in terms of radius is ...
C = 2πr
You are being asked to write this as a function named "f". That will be ...
f(r) = 2πr
Answer:
F
Step-by-step explanation:
If you used the first one
(4÷4) (4÷4) = 1 which is correct.
input the values in the equations and check each one
Answer: 5km per hour
Step-by-step explanation:
You'd do 20/number of hours so you get 1 hour and you'll get his walking speed