Question 456556
4)
g/s+g - g/s-g 
g(s-g)-g(s+g)/(s+g)(s-g)
(gs-g^2-gs-g^2)/(s^2-g^2)
=-2g^2/(s^2-g^2)
or 2g^2/(g^2-s^2)
.
Ed