Question

Выполните действия:
с/(с^2-9)+с/(с^2-9)=
x/y-x/(x+9)=
5/(6m+6)-3/(2m+2)=
a/(a-b)-a^2/(a^2-b^2 )=
3/(x+2y)+3x/(x^2+4xy+〖4y〗^2 )=
(3x+1)/3x-(2y+1)/2y+(3x-y)/6xy=
1/2+x/y+y/x=