Trigonometry Identity Simple question

Question

Hi, it may be a simple misunderstanding of how to work out numerator/denomiator fractions, but confused with the following. Why does (1+\tan x)/(1-\tan x)=(1-\tan x+2\tan x)/(1-\tan x)?

Answer 1

(1+tanx)/(1-tanx) = (1-tanx + 2tanx)/(1-tanx)

(1+tanx)/(1-tanx) =(1+tanx)/(1-tanx)

2tanx -tanx = tanx

-tanx +2tanx = tanx

1-tanx+2tanx = 1-tanx