Answer:

Step-by-step explanation:
In this question, you would solve for "a".
Solve:
K = 4a + 9ab
Since we have our "a" on the same side, we can factor it out from the variables:
K = a(9b + 4)
To get "a" by itself, we would have to divide both sides by 9b + 4:
K/9b+ 4 = a
Your answer would be K/9b+ 4 = a
It would look like this: 
Answer:
Hence, the model that best represents the data is:

Step-by-step explanation:
We are given a table that shows the estimated number of lines of code written by computer programmers per hour when x people are working.
We are asked to find which model best represents the data?
So for finding this we will put the value of x in each of the functions and check which hold true that which gives the value of y i.e. f(x) as is given in the table:
We are given 4 functions as:
A)

B)

C)

D)

We make the table of these values at different values of x.
x A B C D
2 66.66 49.3 52.5 50
4 94.57 71.44 106.3 104
6 134.14 103.57 160.1 158
8 190.27 150.14 213.9 212
10 269.91 217.64 267.7 266
12 382.85 315.5 321.5 320.
Hence, the function that best represents the data is:
Option C.
y=26.9x-1.3
Vary Directly: y = k*x
Vary Inversely: y = k/x
Because x and y vary directly, our equation will look like the first one.
y = k*x
With the inputted values:
-16 = k * 4
Now, to find k, isolate the variable
k = -16/4 = -4
Your final equation will then look like this:
y = -4 * x