Question

If a,x1,x2,x3 ....xn,b are in ap then sum of xn terms in terms in a,b are

Answer 1

Sn =N/2(a+l),
l=b,N=n+2.
=>Sn=n+2/2(a+b).
Sn is total sum we required sum of xn ,
=>Sn-(a+b).
=>sum of Xn=((n+2/2)-1)a+b,
=>sum=(n/2)(a+b)