Question

If sn denote the sum of n terms of A.P then
s[n+3]-3s[n+2]+3s[n+1]-sn=...????
a]0
b]1
c]n
d]n+1
PLZZZZ ANSWER FAST WITH CORRECT AND FULL SOLUTION

Answer 1

Answer:

0

Step-by-step explanation:

Sn = a1 + a2 + a3 +.....+an

S(n+1) = Sn + (an+d)

S(n+2) = Sn + (an+d) + (an+2d)

S(n+3) =Sn +(an + d) +(an + 2d) +(an+3d)

now....

3S(n+1) = 3Sn +3(an+d)

3S(n+2) = 3Sn + 3(an+d) + 3(an+2d)

therefore....

s[n+3]-3s[n+2]+3s[n+1]-sn=

{Sn +(an + d) +(an + 2d) +(an+3d} - {3Sn + 3(an+d) + 3(an+2d) } + {3Sn +3(an+d)} - Sn

= 0