Question

four times the 4th term of ap is equal to 18 times its 18th term find 22nd term

Answer 1

step by step please thnks me

Answer 2

given that

$4 t_{4} = 18 t_{18}$

we know that,

$t_{m} = a + (n - 1)d$

4(a+(4-1)d)=18(a+(18-1)d)

4(a+3d)=18(a+17d)

4a+12d=18a+306d

18a-4a=12d-306d

14a=(-294d)

a=(-294/14)d

a=(-21d)

now,

$t_{22} = a + (22 - 1)d$

=a+21d

{a=(-21d)}

=(-21d)+21d

=0

Therefore the 22nd term =0