C = 2 pi r
C = 2(13) pi
C = 26 pi
Answer:
x = we can’t find the value of x because -5x has a variable and 9 doesn’t, so we can’t do anything.
Answer:
2/π ≈ 0.637 m/s
Step-by-step explanation:
The rate of change of area with respect to time is ...
A = πr²
dA/dt = 2πr·dr/dt
Filling in given values in the above equations, we can find r and dr/dt.
25π = πr² ⇒ r = 5
20 = 2π·5·dr/dt
dr/dt = 20/(10π) = 2/π . . . . meters per second
The radius is increasing at the rate of 2/π ≈ 0.637 meters per second.
Answer:
21
Step-by-step explanation:
You need to use the rule that they gave you (1.5t+3). Since t represents the time in weeks, replace t with 12. Now multiply. 1.5x12=18. 18+3=21