Question

The 8th term of an Ap is 0 prove that its 38th term th term triple its 18

Answer 1

Let first term be a and common difference be d
Given: 8th term of A.P.=0 i.e. a8=0
Since nth term of A.P. = a+(n-1)d
So, a+ 7d=0
a=-7d
Now , to show
(38th term of A.P)=3(17th term of A.P.)
i.e. to show a38=3(a18)
i.e. to show a+37d=3(a+17d)
Take L.H.S.
a+37d=-7d+37d=30d
Take R.H.S.
3(a+17d)=3(-7d+17d)=3(10d)=30d
Since L.H.S.=R.H.S.
Hence proved