>>418
(1)
{(x+1)'(2x-1)-(x+1)(2x-1)'}/(2x-1)^2
={(2x-1)-2(x+1)}/(2x-1)^2
=(-3)/(2x-1)^2

(2)
(cos2x)(2x)'
=2cos2x

(3)
(x)'logx+x(logx)'
=logx+1

(4)
e^(-x^2)*(-x^2)
=-2xe^(-x^2)