Question

Determine the AP whose 3rd term is 5 and the 7th term is 9.​

Answer 1

Answer:

According to the question

a+2d=5.......१

a+8d=9 ........२

form eq 1 and 2

-6d= -4

d=2/3

put d in eq 1

a=5- 4/3

a= 15-4 /3

a= 11/3

AP 11/3 , 13/3 , 5 , 17/3 , 19/3 .............

Answer 2

Answer:

a+2d = 5-----(1)

a+6d = 9-----(2)

a = 5 -2d

putting value of a in equation (2) we get,

5-2d + 6d = 9

5+4d = 9

4d = 9-5

4d= 4

d = 1

Now,

we get d= 1

a+2(1) =5

a+2=5

a = 3

So, a = 3 and d= 1.

Hence, AP is :- 3,4,5,6,7,8,9,10...........

Step-by-step explanation:

I hope it helps you.