Question

If th term of AP is 7-4n. Find the sum of its first ten terms

1) 155
2) 300
3) 150
41​

Answer 1

Answer:

Given:tn=7−4n

⇒t1=7−4×1=7−4=3

⇒t2=7−4×2=7−8=−1

Common difference=d=t2−t1=−1−3=−4

Sum of first 5 terms=S5=25[2×3+(5−1)(−4)] using Sn=2n[2a+(n−1)d]

S5=25[6−16]=25×−10=−25

Answer 2

Answer:

ewtsww4e4e5r5rr5ryryryryrur6rududuudyrudhdhdd GJ

Step-by-step explanation:

No the reciprocal of a) 6 b) 2/7