Question

Determine an ap whose third term is 9 and when fifth term is subtracted from 8 we get 6

Answer 1

Using the formula of finding nth term of AP = a+(n-1)d

The AP is : 16, 25/2, 9.....

Hope it helps you...

Answer 2

Answer:

A.P. : 16,12.5,9....

Step-by-step explanation:

Formula of nth term = $a_n=a+(n-1)d$

Substitute n = 3

$a_3=a+(3-1)d$

Since we are given that  third term is 9

So, a+2d=9  ---1

Substitute n = 5

$a_5=a+(5-1)d$

$a_5=a+4d$

now we are given that when fifth term is subtracted from 8 we get 6

So, 8-(a+4d) =6

8-a-4d =6

a+4d=2 --2

Subtract 1 from 2

a+4d-(a+2d)=2-9

a+4d-a-2d=2-9

2d=-7

d=-7/2 =-3.5

So, Substitute value of d in 2 to get value of a

a+4(-3.5)=2

a-14=2

a=16

$a_2$   = a+d=16-3.5=12.5

$a_3$   = a_2+d=12.5-3.5=9

So, A.P. : 16,12.5,9....