I'm doing math through correspondence so material is not explained very well. I would appreciate if someone could explain this to me. This lesson is review of set theory and first degree equations.

Question

Indicate whether each of the following statements is true or false. If the statement is false, explain why it is false.

a) 3/4EQ
b) the square root -31 ER
c) 0EI
d) -2EW

Answer 1

I will translate and let you make the attempts:
a) ℚ is the set of rational numbers, which can be obtained as the quotient of two integers. This includes fractions, decimal numbers (repeating or not), and all integers.
So
(3/4) ∈ ℚ
is true or not?

b) ℝ is the set of real numbers,. It includes all rational numbers (ℚ), integers (ℤ) and all other numbers that are not complex, such as √(2), π, etc.
So
√(-1) ∈ ℝ

c) I do not know what I represents. The usual symbol for integers is ℤ, or ℕ for natural numbers, which are non-negative integers. If your book defines integers as I, the equivalent question would be:
0 ∈ ℤ

d) Natural numbers are non-negative integers.
I do not know what W stands for. Look carefully to see if it is not actually a fancy N, as in ℕ. So is the following statement true?
-2 ∈ ℕ