Question

The 4th term of an AP is 11. The sum of the 5th and 7th term of this AP is 34.find its common difference. From arithmetic progression

Answer 1

4th term = 11

a+3d =11

a =11-3d ----1equation

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5th term + 7th term =34

a+4d +a+6d =34

Putting the value of a from 1equation,

11-3d +4d +11-3d +6d =34

22 -6d +10d =34

4d =34-22

4d =12

d =12/4

d =3

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Putting the value of d in 1equation,

a +3d = 11

a +3(3) =11

a +9=11

a =11-9

a =2


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1st term = 2

Common difference = 3
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I hope this will help you


-by ABHAY

Answer 2

Hii friend,

a + 3d = 11......(1)

And,

a + 4d + a + 6d = 34

2a +10d =34.......(2)

From equation (1) we get,

a +3d = 11

a = 11-3d.......(3)

Putting the value of a in equation (2)

2a + 10d = 34

2× (11-3d) + 10d = 34

22 -6d +10d = 34

4d = 34-22

4d = 12

d = 12/4

d = 3

Putting the value of D in equation (3)

a = 11-3d

a = 11 - 3 × 3 = 11-9= 2

Therefore,

First term = (2)

And,

Common difference = 4


HOPE IT WILL HELP YOU... :-)