You can write down finite sets as lists. For instance is the set with the three elements -1, and . For sets with infinitely many elements this becomes impossible, so there are other ways to write them down. I don't know. R denotes the set of all real numbers, consisting of all rational numbers and irrational numbers such as .
C denotes the set of all complex numbers.
Write the set of all real numbers strictly between -2 and in interval notation and in set notation. Write the set in set notation. Write the unbounded set in both interval notation and set notation. Mark the set on the real number line. Write down the set of solutions to the inequality in all three notations.