Question

The number of terms to be added to make the sum 52 in the series (– 8) + (– 6) + (– 4) + .... is

Answer 1

let X

-8+-6+-4+X=52

14+-4+X=52

-4+X=52-14

-4+X=38

X=38+4

X=42

Answer 2

Answer:

$13$

Step-by-step explanation:

$S_n\;=\;52\;=\;\frac{n}{2}[2(-8) + (n - 1) 2]\;=\;52$

$n(2n - 18)\;=\;104$

$n(n - 9)\;=\;52$

∴ $n\;=\;13$