Question

an arithmetic series is such that the ninth term is zero and the sum of first 25 terms is 50.the first term of the series?

Answer 1

just plug and chug:

a+8d = 0
25/2 (2a+24d) = 50

8d = -a, so

25/2 (2a-3a) = 50
a = -4

Answer 2

Thank you God bless you :)