Question

The 4th term of AP is zero .prove that the 25th term of the AP .is three times it's 11th term

Answer 1

an=0
n=4
25th=a+24d
11th=a+10d
4th=a+3d=0
a=-3d

a+24d=3(a+10d)
LHS
a+24d
-3d+24d
=21d

RHS
3(a+10d)
3a+30d
3×-3d+30d
-9d+30d
=21 d

since LHS=RHS
hence proved....

Answer 2

for u .. .... my friends...