Question

If f(x) = [x] - 5, what is (86)?

Answer 1

`81`

Explanation:

I am assuming that you are asking what is [x] - 5 if f(86).

When you have this kind of question, what you do is to substitute the variable inside the parenthesis, so like what is says, f(x). If the question replaces the variable x with 86, that means you input the number into the equation.

So [x] - 5, if f(86).

Substitute:

86 - 5

`81`