Given:
Prime numbers can be expressed as a sum and difference of 2 prime numbers.
To find:
The prime numbers that can be expressed as a sum and difference of 2 prime numbers.
Solution:
Prime numbers are the positive integers which are greater than 1, divisible by only 1 and itself.
Prime numbers are 2, 3, 5, 7, 11, 13, 17, 19,... .
Only 2 is the even prime number.
The sum and difference of two odd integers is always an even number. So, we need to take one even prime number and one odd prime number to add and subtract the numbers to get a prime number.
Therefore, 5 is the only prime number that can be expressed as a sum and difference of 2 prime numbers.