The sum of the 4th and 8th terms of an AP is 24 and the sum of the 6th and 10th terms is 44. Find the 5 term of an ap
Answers
5th term of an A.P = 7
Step-by-step explanation:
Given :-
- The sum of 4th and 8th term of an A.P is 24.
- the sum of the 6th and 10th terms is 44 .
To find :-
- find the 5th term of an A.P
Solution :-
4th term of an A.P = a + 3d
8th term of an A.P = a + 7d
Sum of 4th term and 8th term = 24
a + 3d + a + 7d = 24
2a + 10d = 24
divided by 2
a + 5d = 12 ...........eq.(1)
6th term of an A.P = a + 5d
10th term of an A.P = a + 9d
Sum of 6th term and 10th term = 44
a + 5d + a + 9d = 44
2a + 14 = 44
divided by 2
a + 7d = 22 ..........eq.(2)
Subtract eq.(1) from eq.(2)
a + 7d = 22
a + 5d = 12
2d = 10
⟼ d = 10/2
⟼ d = 5
Put the value of d = 5 in eq.(1) we get :-
⟼ a + 5d = 12
⟼ a + 5 × 5 = 12
⟼ a + 25 = 12
⟼ a = 12 – 25
⟼ a = –13
Now, 5th term of an A.P = a + 4d
Put the value of a and d we get :-
⟼ a_5 = a + 4d
⟼ a_5 = –13 + 4 × 5
⟼ a_5 = –13 + 20
⟼ a_5 = 7
Hence, 5th term of an A.P = 7
Here,
- a = first term of an A.P
- d = common difference of an A.P