Question

The fourth term of an ap is zero prove that the 25th term of an ap is 3 times its 11th term​

Answer 1

Answer:

a+3d=0

a= -3d

25th term = a+24d = -3d+24d=21d

11 th term = a+10d = -3d+10d= 7d

21d= 3* 7d

Hence 25th term is three time the 11th term

Hope its help you ❤

Answer 2

☆Given

t4=0

To prove:-

T25= 3×t11

Proof

t4=a+(n-1)d

0 =a+3d

a=-3d

Now,25 th term

25=a+(n-1)d

=>-3d+(25-1)d

21d

Now 11th term

t11=a+(n-1)d

=>-3d+10d

7d

ATQ

multiply by 3

=7d×3

=21

Here if we multiply the 11th term by 3 it equals to the 25th term