Answer:
D. 18.68
Step-by-step explanation:

Applying PEMDAS as order of operations.
Solving the exponents first ![[(\frac{2}{5})^2=\frac{4}{25}]](https://tex.z-dn.net/?f=%5B%28%5Cfrac%7B2%7D%7B5%7D%29%5E2%3D%5Cfrac%7B4%7D%7B25%7D%5D)

Multiplying ![[53\times \frac{4}{25}=8.48]](https://tex.z-dn.net/?f=%5B53%5Ctimes%20%5Cfrac%7B4%7D%7B25%7D%3D8.48%5D)

Dividing ![[27\div \frac{5}{3}=16.2]](https://tex.z-dn.net/?f=%5B27%5Cdiv%20%5Cfrac%7B5%7D%7B3%7D%3D16.2%5D)

Adding and subtracting.

Given:
The growth of a sample of bacteria can be modeled by the function

where, b is the number of bacteria and t is time in hours.
To find:
The number of total bacteria after 3 hours.
Solution:
We have,

Here, b(t) number of total bacteria after t hours.
Substitute t=3 in the given function, to find the number of total bacteria after 3 hours.



Therefore, the number of total bacteria after 3 hours is 119.1016.
Let D be Daniel's present age, then we can represent Kevin's present age as 3D because Kevin is 3 times as old as Daniel.
We can write an expression for Daniel's age 4 years ago as D-4 and Kevin's age 4 years ago as 3D-4.
We are told that 4 years ago Kevin was 5 times as old as Daniel. We can write this information as:
Now let us solve our equation to find Daniel's present age.




Daniel's present age is 8 years. Now we will multiply 8 by 3 to get Kevin's present age as Kevin is 3 times old as Daniel.

Therefore, Kevin is 24 years old now.
i can barly read the image when i open it but, i think its d
Answer:
12.8 units
Step-by-step explanation:
25.6/8 = a/4
a = 4 × 25.6/8
a = 12.8