Question

The sum of 7 terms is 49 and that of 17 terms is 289.find the sum of n terms.(A.P.)

Answer 1

Answer:

n(n+1)divided by 2

Step-by-step explanation:

It is the formula for finding the sum till n

Answer 2

Step-by-step explanation:

S7=49

S17=289

Now you have to make two equation and solve them