Question

What is the domain of f(x) = 5x – 7?

x
x < –7
x > 0
x

Answer 1

d

Explanation:

Answer 2

Answer: Choice D) x is a real number

Reason:

We can replace x with any number we want without any restriction. There's no issues dealing with division by zero errors for instance, and we also don't have negatives under square roots to worry about. The domain of any linear function is always "the set of all real numbers".

Extra info: The domain in interval notation is
`(-\infty, \infty)` which could be thought of as
`-\infty < x < \infty`, i.e. x is between negative infinity and positive infinity.