I need help with Sigma notation

[From: ] [author: ] [Date: 11-04-23] [Hit: ]

30
E (5i-1)
i=1

how do you solve this faster and also i need help :D

30
E (5i-1)
i=1

= 30[5*29/2 -- 1] = 30 [72.5 -- 1] = 30[71.5] = 2145

=5Ei-E1=5X30X31/2-30=2295
NB Ei for i=1 to n =n(n+1)/2; Ec for i=1 to n =nc

keywords: Sigma,help,need,with,notation,I need help with Sigma notation