Find dy/dx if $\displaystyle y=(u^2+5)^{0.5}, u =(1-x)/(1+x); x=-2$

can someone check my work? let me know if i have anything wrong..

$\displaystyle y=({((1-x)/(1+x))^2+5})^{0.5}$

$\displaystyle y=(1-x)/(1+x)+5^{0.5}$

$\displaystyle dy/dx={(-1)(1+x)-(1-x)(1)}/(1+x)^2$

$\displaystyle =(-2)/{(1+x)^2}$

$\displaystyle at x=-2 $

$\displaystyle dy/dx=-2/{(1-2)^2}$

$\displaystyle =-2$