4(x + 2) - 1/2x = 22
4x + 8 - 1/2x = 22
3.5x + 8 = 22
-8 -8
3.5x = 14
/ 3.5 /3.5
x = 4
Amount of water in the pool at the end of the day is 5457798.7 gallons
<u>Explanation:</u>
Given:
Initial amount of water in the pool = 45,000 gallons
Increase in amount = 0.75 in per minute
Time, t = 1 day
t = 24 X 60 min
t = 1440 min
So,
Increase in amount of water in 1 day = 0.75 in X 1440
= 1080 in
Volume of 1080 in of water = (1080 in)³
Volume from cubic inch to gallon = 5453298.7 gallon
Amount of water in the pool at the end of the day = 45000 + 5453298.7 gallon
= 5457798.7 gallon
Given:
Initial number of bacteria = 3000
With a growth constant (k) of 2.8 per hour.
To find:
The number of hours it will take to be 15,000 bacteria.
Solution:
Let P(t) be the number of bacteria after t number of hours.
The exponential growth model (continuously) is:
Where, 
is the initial value, k is the growth constant and t is the number of years.
Putting 
in the above formula, we get
Taking ln on both sides, we get
![[\because \ln e^x=x]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Cln%20e%5Ex%3Dx%5D)
Therefore, the number of bacteria will be 15,000 after 0.575 hours.
