Y = (2-x) / [(1-2x) (1 + x)]

y=(2-x)/[(1-2x)(1+x)]
=[(1-2x)+(1+x)]/[(1-2x)(1+x)]
=1/(1-2x)+1/(1+x)
The n-th derivative of 1 / (1-2x) is
(-1)^n·n!/(1-2x)^(n+1)·(-2)^n
=2^n·n!/(1-2x)^(n+1)
The n-order derivative of 1 / (1 + x) is
(-1)^n·n!/(1+x)^(n+1)
∴ ……