Question

if.7times the 7th term of an is equal to 11 time the 11th term then show that its 18th is zero

Answer 1

hope it will be helpful to you

Answer 2

Answer:

→ a₁₈ = 0 .

Step-by-step explanation:

▶ Given :-

→ 7a₇ = 11a₁₁ .

▶ To prove :-

→  a₁₈ = 0.

Solution :-​

We have,

=> 7a₇ = 11a₁₁ .

=> 7( a + 6d ) = 11( a + 10d ) .

=> 7a + 42d = 11a + 110d .

=> 11a - 7a = 42d - 110d .

=> 4a = - 68d .

=> 4a + 68d = 0 .

=> 4( a + 17d ) = 0 .

=> a + 17d = 0/4 .

=> a + ( 18 - 1 )d = 0.

∴ a₁₈ = 0 .

✔✔ Hence, it is proved ✅✅.

THANKS

#BeBrainly.