the sum of the 4th and 8th terms of an AP is 24 and the sum of the 6th and 10th term is 44. Find the first 3 terms of the AP
Answers
Given:
a4+a8=24
Now,
a+3d+a+7d=24
2a+10d=24
a+5d=12------(1)
Also,
a6+a10=44
a+5d+a+9d=44
2a+14d=44
a+7d=22-----(2)
Subtracting (2) from (1),
-2d=-10
d=5
Substituting d=5 in (1),
a+5(5)=12
a+25=12
a=12-25
a=-13
Therefore, the first three terms of the Arithmetic progression are:
a=-13
a+d=-13+5==-8
a+2d=-13+2(5)=-13+10=-3
Answer: -13,-8,-3....
Answer:
- 13 , - 8 , - 3 .
Step-by-step explanation:
Let the first term a and common difference be d.
We know :
t_n = a + ( n - 1 ) d
t_4 = a + 3 d
t_8 = a + 7 d
We have given :
t_4 + t_8 = 24
2 a + 10 d = 24
a + 5 d = 12
a = 12 - 5 d ....( i )
t_6 = a + 5 d
t_10 = a + 9 d
: t_6 + t_10 = 44
2 a + 14 d = 44
a + 7 d = 22
a = 22 - 7 d ... ( ii )
From ( i ) and ( ii )
12 - 5 d = 22 - 7 d
7 d - 5 d = 22 - 12
2 d = 10
d = 5
We have :
a = 12 - 5 d
a = 12 - 25
a = - 13
Now required answer as :
- 13 , - 8 , - 3 .
Finally we get answer.