Answer
$y'=\frac{-5}{2\sqrt x\times(\sqrt x/2-1)^{11}}$
Work Step by Step
Find y and u:
$y=u^{-10}$
$u=\sqrt x/2-1$
First, find the derivative of y and u. Don't forget to apply chain rule for y':
$y'=-10u^{-11}\times u'$
$u'=\frac{1}{4\sqrt x}$
Then plug in u and u' into y':
$y'=-10(\sqrt x/2-1)^{-11}\times\frac{1}{4\sqrt x}=\frac{-5}{2\sqrt x\times(\sqrt x/2-1)^{11}}$
