Ответ:

1)[tex]-\frac{6}{a}[/tex]

3)[tex]-\frac{1}{2m}[/tex]

Объяснение:

1) [tex]\frac{3a - b}{ab} - \frac{5b+3a}{ab} = \frac{-6b}{ab} = \frac{-6}{a} = -\frac{6}{a}[/tex]

3)[tex]\frac{5b - m^{2} }{4m^{3}} - \frac{m^{2} + 5b}{4m^{3}} = \frac{-2m^{2}}{4m^{3}} = \frac{-1}{2m} = -\frac{1}{2m}[/tex]