The question does not make sense.
The sum ad difference of two terms comprise only two terms so there are not 7 terms.
7 terms
-7 & -14
The answer to your question is 10 and three.10 + 3 = 13 (Sum)10 - 3 = 7 (Difference)I hope this helps.
7 & 14
7 and 4
19 and -7
5 and -2
6 and 7
7 and 15.
7 and 9
7 & 9
The two numbers are -14 and -7. -14 + -7 = -21 -7 - -14 = 7