Question

calculate the sum of first 25 terms of arthematic sequence 11,22 ,33....​

Answer 1

11,22,33...........

a=11

d=22-11=11

n=25

view the image below and then,,

So the sum of first 25 terms of the arithmetic sequence is 3575

Hope this helps you

Answer 2

Step-by-step explanation:

sum of first Nth term in AP= n/2 [2a+ (n-1) d]

here n = 25,

first term a= 11,

d= 22-11

d= 11

now

sum of first 25 terms=25/2 [ 2×11+(25-1) 11]

= 25/2 ( 22+ 24×11)

= 25/2 ( 286)

= 25× 143

= 3575 ans