Question

find the Ap

(ix) given a=3, n = 8, S= 192, find d.
(x) given l= 28, S = 144, and there are total 9 terms. Find a.​

Answer 1

Answer:

192=4(6+7d)

6+7d =48

7d=42

d=6

144=4.5(@+28)

Answer 2

Step-by-step explanation:

Given, l = 28.

s = 144 .

n = 9 .

∴ Sum of n terms, s = 144

⇒ n/2 (a+l)=144.

⇒ 9/2 (a+28)=144

⇒a+28=144× 2/9

⇒a=32−28

⇒a=4