the sum of four consecutive terms of an ap is 2. the sum of the third and fourth term is 11 .
find the terms
Answers
Given:
Sum of 4 consecutive numbers of an AP is 2.
Sum of the 3rd and 4th term is 11.
To Find:
The terms
Solution
Define x :
Let the first term be a
First term = a
Second = a + d
Third term = a + 2d
Fourth term = a + 3d
Form the equations:
Sum of 4 consecutive numbers of an AP is 2.
a + (a + d) + (a + 2d) + (a + 3d) = 2
4a + 6d = 2
2a + 3d = 1 ----------------------- [ 1 ]
Sum of the 3rd and 4th term is 11.
(a + 2d) + (a + 3d) = 11
2a + 5d = 11 ----------------------- [ 2 ]
[2 ] - [ 1 ]:
2d = 10
d = 5
Sub d = 5 into [ 1 ]
2a + 3(5) = 1
2a + 15 = 1
2a = -14
a = -7
Find the terms:
First term = a
First term = -7
Second term = a + d
Second term = -7 + 5
Second term = -2
third term = a + 2d
third term = -7 + 2(5)
third term = 3
Fourth term = a + 3d
Fourth term = -7 + 3(5)
Fourth term = 8
Answer: The terms are -7, -2, 3 and 8