Question

please. plzzzzzzzzzzzz answer

Answer 1

Given a4 = 0

That is (a + 3d) = 0

⇒ a = - 3d → (1)

nth term of AP is given by an = a + (n – 1)d

a11 = a + 10d = – 3d + 10d = 7d  [From (1)]

a25 = a+ 24d = – 3d + 24d = 21d  [From (1)]

      = 3 x 7d

Hence a25 = 3 x a11

Answer 2

Answer:

Step-by-step explanation:

A4=0

A+3D=0

A=-3D............1

A25=A+24D

=-3D+24D

=21D......2

A11=A+10D

=-3D+10D

A11=7D.....3

Multipying 3 by 3,

3A11=21D....4

From 2 and 3,

A23=3A11

hence proved.

Hope it helps....