Question

if 7 times the 7th term of an ap is equal to 11 times its 11th term then find its 18th term​

Answer 1

Step-by-step explanation:

7 ( 7th term) = 11( 11th term)

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

7a + 42d = 11a + 110d

11a - 7a + 110d - 42d = 0

4a + 68d = 0

4( a + 17d) = 0

a + 17d = 0 -------(1)

a18= a + 17d

a18 = 0 ( from 1)

Hope it helps you.