Hi forum,

I saw this trollmath on youtube. i dont claim its correct, but i cant understand where the mistake is. help

Consider a geometric series as follows:

$\displaystyle S = 2 + 4+ 8 + 16 + ......$ [1]

$\displaystyle 2S = 4 + 8+ 16 + ...... $ [2]

[2]-[1]

$\displaystyle S = 2 $

Clearly the last line is false, but where is the mistake?