答：
设t=√x,x=t^2,dx=2tdt
∫ √x /(1+√x)^5 dx
=∫ [t /(1+t)^5 ]*2t dt
=2∫ (t+1-1)^2 /(1+t)^5 dt
=2 ∫ 1/(1+t)^3 -2/(1+t)^4 +1/(1+t)^5 d(t+1)
=-1/(1+t)^2 +(4/3) /(1+t)^3 -(1/4)/(1+t)^4+C
=-1/(1+√x)^2 +(4/3) /(1+√x)^3 -(1/4)/(1+√x)^4+C