3) 4,25 - 3,6 : 1 7/20 + 8 1/4 \(\cdot\) 1 52/99 - 12 2/3

Решение:

3. Третий пример:

1. \( 4,25 = 4\frac{1}{4} = \frac{17}{4} \)
2. \( 3,6 = 3\frac{6}{10} = 3\frac{3}{5} = \frac{18}{5} \)
3. \( 1\frac{7}{20} = \frac{27}{20} \)
4. \( \frac{18}{5} : \frac{27}{20} = \frac{18}{5} \cdot \frac{20}{27} = \frac{2}{1} \cdot \frac{4}{3} = \frac{8}{3} \)
5. \( 8\frac{1}{4} = \frac{33}{4} \)
6. \( 1\frac{52}{99} = \frac{151}{99} \)
7. \( \frac{33}{4} \cdot \frac{151}{99} = \frac{1}{4} \cdot \frac{151}{3} = \frac{151}{12} \)
8. \( 12\frac{2}{3} = \frac{38}{3} \)
9. \( \frac{17}{4} - \frac{8}{3} + \frac{151}{12} - \frac{38}{3} = \frac{17}{4} + \frac{151}{12} - \frac{8}{3} - \frac{38}{3} = \frac{17}{4} + \frac{151}{12} - \frac{46}{3} = \frac{51 + 151 - 184}{12} = \frac{202 - 184}{12} = \frac{18}{12} = \frac{3}{2} = 1,5 \)

Ответ: 1,5