sum of 5th term to 8th term of an arithmetic sequenceis 70. sum of 10th term to 13th term is 130.find 9th term,7th term and Xn
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a+4d+ a+7d= 70
=>2a+ 11d= 70
a+12d+ a+9d= 130
=>2a+21d= 130
by elimination method,
2a+21d = 130
2a+ 11d = 70
- - -
=>10d = 60
=>d = 6
2a+11(6) = 70
=>2a = 70-66
=>2a = 4
=>a = 2
a+8d = 2+ 8(6)
= 2+ 48
= 50
a+ 6d = 2+ 6(6)
= 2+36
= 38
PLZ MARK THE BRAINLIEST
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