Question

Question #4ab13

Answer 1

`f(a)` means that you substitute "a" for every x within `f(x)` and then do the calculations.

Explanation:

`f(5)` means you substitute 5 for x everywhere you see x in the given function, f(x):

`f(5) = -8|-10+5| larr` we substituted 5 for x.

Now, we just do the calculations.

`f(5) = -8|-5| larr` this is `-10+5 = -5`

`f(5) = -8(5) larr` this is `|-5| = 5`

`f(5) = -40 larr` answer

Answer 2

`-40`

Explanation:

So, the question is, if `f(x)` equals `-8abs(-10+x)`, what does `f(5)` equal.

Well, let's start by replacing `x` with `5`, because now the equation asks for the function of `5`:

`-8abs(-10+5)`

Let's simplify the values within the grouping system (`abs(color(white)(000))`)

`-8abs(-5)`

Because absolute value is a measure of distance, it can never represent a negative number. There's no such thing as `-5` feet. Even if a person moves backward `10` meters, they have moved `10` meters, but it is not negative.

What that means is, an absolute value of a negative number is a positive number. So, `abs(-5)` is `5`:

`-8(5)`

`-40`