Final answer:
In mathematics, the provided sets A (x ∈ ℤ ) and C (x ∈ ℤ ) are subsets of set r = x ∈ ℤ , because all numbers divisible by 4 or 6 are also divisible by 2. Sets B and D are not subsets as they include elements not divisible by 2.
Step-by-step explanation:
The question asks which sets are subsets of the set r = x ∈ ℤ . A subset is a set in which every element is also contained in another set. We need to check which of the provided sets have all their elements divisible by 2.
- Set A = x is divisible by 4 is a subset of r, because every number divisible by 4 is also divisible by 2.
- Set B = x is divisible by 3 is not a subset of r, because not all numbers divisible by 3 are divisible by 2.
- Set C = x ∈ ℤ is a subset of r, because every number divisible by 6 is also divisible by 2.
- Set D = x ∈ ℤ is not a subset of r, because not all numbers divisible by 5 are divisible by 2.
Hence, the sets that are subsets of r are A and C.