Question

Please explain this question​

Answer 1

Answer:

{(P + R) (R + Q - 2P)} / 2(Q - P)

Step by step explaination:

tn = a + (n-1) d

R = P + (n-1) (Q - P)

R - P = (n-1) (Q - P)

(R - P)/ (Q - P) = n - 1

i.e. n = (R - P)/ (Q - P) + 1

n = {(R - P) + (Q - P)} / (Q - P)

n = (R + Q - 2P) / (Q - P)

Sn = [n/2] x (First term + Last Term)

= [{(R + Q - 2P) / (Q - P)} / 2] x  (P + R)

= {(P + R) (R + Q - 2P)} / 2(Q - P)

Third option is the correct answer.

Answer 2

Answer:

option C

Step-by-step explanation:

HOPE it helps to clear your concept

please study in these hard times ☺☺✌✌