To find the formula to find radius, solve for r using the formula for circumference.
to solve:
1. divide each side by 2

2. you get
r = c/2
Answer:
roots: 1 and 3
k = 3
Step-by-step explanation:
2 roots: p and p+2
(x-p) (x-p-2) = x² - 4x + k
x² -2px -2x + p² + 2p = x² - 2 (p+1)x + (p² + 2p) = x² -4x + k
-2 (p+1) = -4
p+1 = 2
p = 1 ... root 1
p' = 1+2 = 3 ... root 2
k = p² + 2p = 3
check: (x-1) (x-3) = x² - 4x + 3 = x² - 4x + k
Let us assume as at when they meet, the time elapsed is x hours.
Fred 3 mi/h
John 2 mi/h
Distance = speed * time
Fred = 3x
John = 2x
Houses are 4miles apart.
So: 3x + 2x = 4 5x = 4
x = 4/5 hour = 0.8 hour or 0.8*60 = 48 minutes
Time elapsed is 0.8 hour or 48 minutes.