(3-m)/(2m-4)÷[m+2-5/(m-2)]
=(3-m)/(2m-4)÷[(m^2-4-5)/(m-2)]
=(3-m)/(2m-4)÷[(m^2-9)/(m-2)]
=(3-m)/(2m-4)÷[(m-3)(m+3)/(m-2)]
=(3-m)/(2m-4)*(m-2)/(m-3)(m+3)
=-(m-3)/2(m-2)*(m-2)/(m-3)(m+3)
=-1/2(m+3)
=-1/(2m+6)
(3-m)/(2m-4)÷[m+2-5/(m-2)]
=(3-m)/(2m-4)÷[(m^2-4-5)/(m-2)]
=(3-m)/(2m-4)÷[(m^2-9)/(m-2)]
=(3-m)/(2m-4)÷[(m-3)(m+3)/(m-2)]
=(3-m)/(2m-4)*(m-2)/(m-3)(m+3)
=-(m-3)/2(m-2)*(m-2)/(m-3)(m+3)
=-1/2(m+3)
=-1/(2m+6)