Question

if 9th term of an a.p is 0 ,prove that its 29 th term is double the 19th term.

Answer 1

Hii ☺ !!

Given :-

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

LHS = RHS........PROVED......

Answer 2

Answer:

Let the first term ot hte a. p. =a and the common difference = d t9= 0

t9 = a+ 8d =0

a=-8d

and

t19= a+ 18d

=-8d+18d

t19=10d............................1

and

t29=a+28d

=-8d+28d

=20d

t29=20d..................................2

hence from 1&2

it is proved

Step-by-step explanation: