3y/(2x+2y)+2xy/(x^2+xy)
=3y/[2(x+y)]+2xy/[x(x+y)]
=3y/[2(x+y)]+2y/[(x+y)]
=3y/[2(x+y)]+4y/[2(x+y)]
=(3y+4y)/[2(x+y)]
=7y/(2x+2y)