Answer:

Domain: 
Step-by-step explanation:
Given

Required
Determine f(x) and its domain
To determine f(x), we replace 5x with x in f(5x)
So, we have:


Take LCM



To get the domain, we set the denominator as



The unit rate is $2.20 for each pencil because 11 divided by 5 is 2.2
Answer:
The value of X is always 1
Using an exponential function, it is found that f(5.5) = 19.8.
<h3>What is an exponential function?</h3>
An exponential function is a function in which the growth rate is a percentage, modeled by:

In which:
f(3.5) = 25 means that:


f(8.5) = 14 means that:

Hence:


![b = \sqrt[5]{\frac{14}{25}}](https://tex.z-dn.net/?f=b%20%3D%20%5Csqrt%5B5%5D%7B%5Cfrac%7B14%7D%7B25%7D%7D)


Hence, the function is given by:

Then, when x = 5.5:

More can be learned about exponential functions at brainly.com/question/25537936
Answer:
x = -3.25
Step-by-step explanation:
2/5 = 0.4
0.4x - 0.2 = -2(3/4)
-2(3/4) = -2/1 * 3/4 = -6/4
0.4x - 0.2 = -6/4
Convert to fraction
2/5x - 1/5 = -6/4
Add 1/5 to both sides
-6/4 + 1/5 = -30/20 + 4/20 = -26/20
2/5x = -26/20
Convert to decimal
0.4x = -1.3
-1.3/0.4 = -3.25
x = -3.25