Question

Find the sum of the first 15 terms of the AP given by 1) Sn=2n-5 2) An=2-3n

Answer 1

Answer:

25

Step-by-step explanation:

If Sn=2n-5

then value of n=15

because we have to find sum of 15 terms

• Now, S15=2×15-5

S15=30-5

=25

Answer 2

Answer:

put n=15 in the given equation the answer will be 25