Step-by-step explanation:
a + a² + a³ + ... = 2a
1 + a + a² + ... = 2 (divide by a, where a could be 0)
Subtract both equations, we have:
-1 = 2a - 2, 2a = 1, a = 0.5.
Hence we have a = 0 or a = 0.5.
