Every function is a rule which tells you how to associate inputs and outputs. The input, also known as independent variable, is often indicated with the letter 
, while the output, also known as dependent variable, is often indicated with the letter 
.
With this notation, we write 
, read "y is a function of x", in the sense that the value of the variable y depends on the value of the variable x, and f is the function that tells you how y depends on x.
In your example, you have 
, which means "subtract four times the input (4x) from 2"
So, it doesn't matter which input you chose (i.e. the value for x), because you will always have to behave this way:
- Pick an input value, x
- Multiply it by four to get 4x
- Subtract this number from 2: 2-4x
Here are some examples of explicit calculations: if I choose 
and input, the workflow will be
- Pick an input value, 2
- Multiply it by four to get 8
- Subtract this number from 2: 2-8=-6
So, if the input is 2, the output is -6
Similarly, if we choose 
as input, we have:
- Pick an input value, 0
- Multiply it by four to get 0
- Subtract this number from 2: 2-0=2
So, if the input is 0, the output is 2. And so on: for every possible value for x you have the correspondant value for y, with the function f telling you how to associate one with the other.
In the top the "f(x)" equals 9, now they are asking you to add onto the 9 by 1 causing it to be 10. If you did the first few you would have noticed that it takes 9 in order to get to 5 from -4.
here are the answers btw:
Answer:
V = 4000 ft³
Step-by-step explanation:
if diameter is 20 then radius is half that, or 10
use formula:
V = 4/3(3)(10)³
V = 4(10)³
V = 4(1000)
V = 4000 ft³
That's not correct. The terms 2a and 3b are not like terms, so we cannot combine them to get 5ab. We simply leave it as 2a+3b.
If you had 2a+3a, then it would simplify to 5a
Similarly, 2b+3b = 5b
Or you could have 2ab+3ab = 5ab
The key is that the variable portions must match up to be able to add them.
