(y-3)/(4y-8)÷[5/(y-2) -(y+2)]
=(y-3)/(4y-8)÷[5-y^2+4]/(y-2).
=-(y-3)/(4y-8)*(y-2)/(y^2-9)
=-[(y-3)/4]/[(y-3)(y+3)]
=-1/[4(y+3)].