Question

if 9th term of ap is 0 .prove that its 29th term is double of its 19th term (solve it without cheating )

Answer 1

Hello !!

9th term = 0

a + 8d = 0

a = -8d

To prove :

29th term = 2 ( 19th term )

a + 28d = 2 ( a + 18d )

-8d + 28d = 2 ( -8d + 18d )

20d = 2 ( 10d )

20d = 20d....... PROVED.......



Hence,


29th term of an ap is equal to double of it's 19th term .