Sequences and Series Part 1

b

r

, b , br → G.P. (|r| ≠ 1)
given a + b + c = xb
⇒ b/r + b + br = xb⇒ b = 0 (not possible)
or 1 + r +

1

r

= x ⇒ x - 1 = r +

1

r

⇒ x – 1 > 2 or x – 1 < –2
⇒ x > 3 or x < – 1
So x can't be '2'