m 9) abc + abm

9) $$\frac{m}{abc} + \frac{c}{abm} = \frac{m^2}{abcm} + \frac{c^2}{abcm} = \frac{m^2 + c^2}{abcm}$$

Ответ: $$\frac{m^2 + c^2}{abcm}$$