Question

solve the arithmetic progression

Answer 1

given,
4th term of AP=0
I.e, a+3d=0
now, according to the problem,
25th term =3×11th term
=>a+24d=3×(a+10d)
=>a+24d=3a+30d
=>a-3a=30d-24d
=>-2a=6d
=>2a+6d=0
=>2(a+3d)=0
=>2×0=0 [a+3d=0]
=>0=0

hope it will help you. if you are satisfied with my answer then mark my answer as brainlist answer please

Answer 2

Let first term is a
and common difference is d
a4 = 0
a+3d = 0

25 th term = a+ 24d = a+3d+21d = 0 + 21d = 21d
11th term = a+10d = a +3d +7d = 0+7d =7d = 3 ×7d = 21d
So 3 × 7d = 21d
3 ×11 th term = 25 th term

Hope it helps....