Given, Sn= Sum of first n terms of an AP Let a and d be the first term and common difference of an AP. ∴S4=
4
2
[2a+(4−1)d]=−34 (∵Sn=
n
2
[2a+(n−1)d]) ⇒2a+3d=−17.....(i) and S5=
5
2
[2a+(5−1)d]=−60 ⇒2a+4d=−24....(ii) On subtracting Eq. (i) from Eq. (ii), we get d=−7 Then, from Eq. (i), 2a−21=−17 ⇒2a=4⇒a=2 Hence, common difference, d=−7 and first term =2