Помогите,чет туплю)

Решите задачу:

$\frac{m}{m^{2}-4}:( \frac{4+m^{2}}{2+m} -m )= \frac{m}{m^{2}-4}:( \frac{4+m^{2}}{2+m} - \frac{m(2+m)}{2+m} )=\frac{m}{m^{2}-4}:( \frac{4+m^{2}-m(2+m}{2+m})=\frac{m}{m^{2}-4}:( \frac{4+m^{2}-2m+m^{2}}{2+m})= \frac{m}{m^{2}-4}:( \frac{4-2m}{2+m})=\frac{m}{-(4-m^{2})}:( \frac{2(2-m)}{2+m})=\frac{m}{-(4-m^{2})}*( \frac{2+m)}{2(2-m)})= \frac{m(2+m)}{-(4-m^{2})(2(2-m))}=\frac{m(2+m)}{-(2-m)(2+m)(2(2-m))} = \frac{m}{-2(2-m)(2-m)}= - \frac{m}{2(2-m)^{2}}$