Question

A.P :- -10,-12,-14,-16,......upto 15 terms​

Answer 1

-10,-12,-14,-16,-18,-20,-22,-24,-26,-28,-30,-32,-34,-36,-38

Hope it helps ❤

Answer 2

Answer:

First term of the given arithmetic series = 12

Second term of the given arithmetic series = 15

Third term of the given arithmetic series = 18

Fourth term of the given arithmetic series = 21

Now, Second term - First term = 15 - 12 = 3

Third term - Second term = 18 - 15 = 3

Therefore, common difference of the given arithmetic series is 3.

The number of terms of the given A. P. series (n) = 14

We know that the sum of first n terms of the Arithmetic Progress, whose first term = a and common difference = d is

S

n

=

2

n

[2a+(n−1)d]

S

14

=

2

14

[2×12+(14−1)3]

S

14

=7[24+39]

S

14

=441

Explanation:

=441