Question

Graph the set and express it in interval notation.
All real numbers between 8 and 12, including 12.

Answer 1

Typically we represent the set of real numbers using a line called the *real number line*:
Since it extends infinitely far in either direction, and each part looks the same, we can use this particular shown part to represent a section of the reals that contains both 8 and 12, marked by dashes:Since we're interested in the real numbers between them, we shade the line segment between them: