The sum of 4th and 8th terms of an A.P is 24 and the sum of 6th and 10th term is 34 find the first term and common difference
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a4+a8=24
a+3d+a+7d=24
2a+10d=24. .........1
a6+a10=34
a+5d+a+9d=34
2a+14d=34. .,.......2
Subtracting 2 from 1
2a+14d=34
2a+10d=24
- - -
4d=10
d=4/10or 2/5
Put d= 2/5 in 1
2a+10×2/5=24
2a+4=24
2a=24-4
2a=20
a=10
a+3d+a+7d=24
2a+10d=24. .........1
a6+a10=34
a+5d+a+9d=34
2a+14d=34. .,.......2
Subtracting 2 from 1
2a+14d=34
2a+10d=24
- - -
4d=10
d=4/10or 2/5
Put d= 2/5 in 1
2a+10×2/5=24
2a+4=24
2a=24-4
2a=20
a=10
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