Answer:
10
Step-by-step explanation:
Its 1/5 likely because my teacher helped me with this problem you welcome:)
Carly : y = 60x + 40
janiya : y = 50x + 80
60x + 40 = 50x + 80
60x - 50x = 80 - 40
10x = 40
x = 40/10
x = 4 <=== so at 4 weeks, they will have the same amount of money <==
The money they have is : y = 60(4) + 40.....y = $ 280 <=
so ur answer is : 4 weeks, $ 280
The function for the height is

f(0) = 5 cos(0) + 7 = 5 + 7 = 12 (verified)
The period is T = 12 hours.
After 4 hours (t = 4), the height is

A graph of f(t) confirms the answer.
Answer: 4.5 ft