Question

the sum n term of an AP is 4n+5n find the AP solve tha questions

Answer 1

Sn = 4n+5n = 9n
So
S1 = 9
Or a1 = 9(fist term of the AP)

S2 = 18
S2-S1 = a2
So
a2= 9

Now d = a2-a1 => 0
So d =0
Now A.P will be :-
9,9,9,9,9...........