Question

if 5th term is 1/7 and 7th term is 1/3 find 35th answrr fstt

Answer 1

Answer:

3

Step-by-step explanation:

5th term = a+4d =1/7

a=1/7-4d ---------1

7th term =a+6d=1/3

1/7-4d+6d=1/3 ---- putting value of a

2d=1/3-1/7

2d=4/21

d=2/21 -----------(2)

Putting value of d in 1

a=1/7-4d

a=-5/21

35th term =a+ 34d

-5/21+4×2/21

=63/21

=3

Answer 2

Answer:

Step-by-step explanation:

let first term = a and common difference = d

tₙ = a + (n-1)d

t₅ = a + 4d = 1/7 --------------> 1

t₇ = a + 6d = 1/3 -----------------> 2

solve 1 and 2

a + 6d = 1/3

a+4d = 1/7

-  -        -

-----------------

2d = 1/3 - 1/7 = 4/21

=> d = 2/21

now substitute the value in equation 1,

a + 4*2/21 = 1/7

=> a = 1/7 - 8/21 = -5/21

now

t₃₅ = -5/21 + 34 * 2/21 = 63/21 = 3.