Question

two APs have the same common difference .the first term of one of these is -1 and that of the other is -8 .what is the difference between their 4th terms​

Answer 1

Answer:

7

Step-by-step explanation:

 Let the common difference of these APs be d.

In APs nth term is given by a + ( n - 1 )d where symbols have their usual meaning.

Required result :

⇒ 4th term of AP with(- 1) - 4th term of AP with - 8

⇒ [ - 1 + ( 4 - 1 )d ] - [ - 8 + ( 4 - 1 )d ]

⇒ [ - 1 + 3d ] - [ - 8 + 3d ]

⇒ - 1 + 3d + 8 - 3d

⇒ 8 - 1

⇒ 7

  Difference between their 4th terms is 7