Question

help with this pleaseee​

Answer 1

Answer:

Sum of 100 terms of the sequence = 15050

Step-by-step explanation:

Given expression which represents a sequence is,

$\sum_{r=1}^{100}(3r-1)$

So the sequence will be,

2, 5, 8, 11, 14..........

So, the given sequence is an arithmetic sequence with,

First term of the sequence 'a' = 2

Common difference 'd' = 5 - 2 = 3

Sum of 'n' terms of an arithmetic sequence is given by,

$S_n=\frac{n}{2}[2a+(n-1)d]$

Here, n = number of terms

a = first term

d = common difference

$S_{100}$ = $\frac{100}{2}[2(2)+(100-1)(3)]$

      = 50[4 + 297]

      = 15050

Therefore, sum of 100 terms of the sequence = 15050