SOLUTION: If the second term of an A.S is 10 and his sum of first two term is 25 find the common difference

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Question 888705: If the second term of an A.S is 10 and his sum of first two term is 25 find the common difference
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
S = ½(2a + (n-1)d)n
an = a + (n - 1)d
25 = 2a + d
10 = a + d
a=15
d=-5