Question

given a, = 4, d=2, S =-14, find n anda.​

Answer 1

Answer:

If we sum the above series, we find that 4 + 2 + 0 - 2 - 4 - 6 - 8 = -14. Therefore, we need n = 7 terms to give the sum as -14 and the final term is a = -8, which answers the question.

Answer 2

Step-by-step explanation:

Given

a = 4

d = 2

s = 14

n = ?

$s = \frac{n}{2} (2a +( n - 1) \times d)$

$14 = \frac{n}{2} (2 \times 4 + (n - 1)2$

$28 = n(8 + (n - 1)2)$

$28 = n(8 + 2n - 2)$

$28 = n(6 + 2n)$

$28 = 6n + {2n}^{2}$

${2n}^{2} + 6n - 28 =0$

I HOPE SOLVE THE QUADRATIC EQUATION WE GET VALUE OF N