Question

Find the sum to n term of the A.P. 5, 2, −1, −4, −7, ...,

Answer 1

In the given problem, we need to find the sum of the n terms of the given A.P. “”.

So, here we use the following formula for the sum of n terms of an A.P.,

Where; a = first term for the given A.P.

d = common difference of the given A.P.

n = number of terms

For the given A.P. (),

Common difference of the A.P. (d) =

Number of terms (n) = n

First term for the given A.P. (a) = 5

So, using the formula we get,

Therefore, the sum of first n terms for the given A.P. is.