Question

find the sum of the following AP 34+3230+.....+10

Answer 1

Hey There!! 
The A.P. is given as: 

34, 32, 30, ... , 10
Here, First Term = a = 34
Common Difference = d = - 2

Let the number of terms be n.
Since 10 is the last term, we can write: 

$T_n=10 \\ \\ \implies a+(n-1)d=10 \\ \\ \implies 34-2n+2=10 \\ \\ \implies 2n=26 \\ \\ \implies \boxed{\textbf{n=13}}$ 

Now, Sum of n terms is given by the formula:   

$S_n = \frac{n}{2}\left(\textrm{First Term + Last Term}\right) \\ \\ \implies S=\frac{13}{2}(34+10) \\ \\ \implies S=\frac{13\times 44}{2} \\ \\ \\ \implies \boxed{\textbf{Sum=286}}$


Hope it helps
Purva
Brainly Community

Answer 2

sorry don't know the answer