Question

An A.P consists of three terms whose sum is 15 and sum af their squares of extreme s is 58. Find the sum of first 50 terms of an A.P​

Answer 1

Step-by-step explanation:

let terms be a-d, a, a+d

sum=3a=15

a=5

(a-d)^2+(a+d)^2 = 2a^2+2d^2 =58

d=2

Sn= n/2(2a+ (n-1)d)

= 50/2(10 +(49*2))

= 25 * 108

= 2700

Sum of first 50 terms is 2700