Question

iv) If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n
terms.
(3 marks)​

Answer 1

Answer:

math is out of mind

Step-by-step explanation:

.......?

Answer 2

Answer:

a1 = 1 , d = 2

and use this formula :- Sn = n/2 ( 2a + ( n- 1) d)

and put value in this