If 9th term of an A.P. is zero,prove that its 29th term is double the

1.	If 9th term of an A.P. is zero,prove that its 29th term is double the 19th term.
Answer» Here,9 the term is 0 so,a+8d=0a= -8d ---(1)Now,A.T.Q,29th term =2(19th term)a+28d=2(a+18d)Putting a= -8d from (1)-8d+28d=2(-8d+18d)20d=2(10d)20d=20dHence proved!!!!!!!! a9=a+8da=-8da19=a+18d=-8d+18d=10da29=a+28d=-8d+28d=20d

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