Question

from progress In an A.P , if common diffirence is 2, sum to n terms is 49, 7th term is 13, then n =

Answer 1

d=2   Sn=49   a7=13

13=a+(n-1)d
13=a+12
a=1

49=n/2(2n)
49=n²
n=7

here is your answer

Answer 2

See we know a+6d=13
So a is 1
Sn=n\2[2a+(n-1)d]
98=n[2+2n-2]
98\2=2n^2
49=n^2
√(7)^2=n
n=7