Question

the sum of 1st 9 terms of an a.s is 45 and the sum of 1st 18 term is 171

d)find the sum of 5th to 14th term​

Answer 1

Step-by-step explanation:

The general term of an AP is an=a+(n−1)d where, a is the first term, d is the common difference and n is the total number of terms in an AP. The sum of first 9 terms of an arithmetic sequence is 45. Similarly, it is given that the sum of the first 18 terms is 171. ... Hence, we will take n=9 for this case.