PLEASE HELP!!!
Expand:
A. 3 + 4 + 5 + 6 + 7
B. 7 + 8 + 9 + 10 + 11 + 12 + 13
C. 7 + 8 +9 + 10 + 11
D. 7 + 11 + 15 + 19 + 23
