Question

Given l=28, S=144 and there are total nine term

Answer 1

Hey MATE!

We know here that l = 28

n = 9

S = 144

So we can apply,

$144 = \frac{9}{2} (a + 28)\\ 288 = 9a + 252 \\ 288 - 252 = 9a \\ 36 = 9a \\ a = 4$
Now we can find d :

$28 = 4 + (9 - 1)d \\ 24 = 8d \\ d = 3$


Hope it helps

Hakuna Matata :))

Answer 2

Answer:

I hope it is helpful..................