Answers

2016-03-11T11:32:34+05:30
S3 = 45
let the 3 yerms be ( a - d ) , a , (a+d )
a - d + a + a + d = 45
3a = 45
a = 15
a + 21 = (a - d ) ( a + d)
15 + 21 = a^2 - d^2
36 = 15^2 - d^2
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