Here's the question you clicked on:
ParthKohli
Show that,\[\rm {1 \over 1 - x} = 1 +x+x^2 + x^3+x^4+x^5\cdots\]
Is that statement even true?
for absolute value of x is less than one.
Oh. Then I think I asked a wrong question.
this is just geometric series ... you get get the same if you expand it binomially.