34 7 45 10

7) $$\frac{34}{45} - \frac{7}{10} = \frac{34 \cdot 2}{45 \cdot 2} - \frac{7 \cdot 9}{10 \cdot 9} = \frac{68}{90} - \frac{63}{90} = \frac{68-63}{90} = \frac{5}{90} = \frac{1}{18}$$

Ответ: $$\frac{1}{18}$$