Final answer:
The numbers 56, 28, and 14 are multiples of 7 and also even, making them part of the subset A within the universal set U of all positive even numbers.
Step-by-step explanation:
The student's question involves identifying which number from a given list is a multiple of 7 and also an even number, making it part of the subset A within the universal set U of all positive even numbers. From the provided options, 56, 28, 36, and 14 are to be evaluated.
If we check each number, we find the following results:
- 56 is a multiple of 7 (7 x 8) and is even.
- 28 is a multiple of 7 (7 x 4) and is even.
- 36 is not a multiple of 7.
- 14 is a multiple of 7 (7 x 2) and is even.
Therefore, the numbers 56, 28, and 14 are in the subset A of U.