3) 1/4+1/2-1/16+ 6,24:0,3-15,8 26-18+1/12 2,3.5+ 2,5

3) Выполним действия:

$$\frac{\frac{1}{4} + \frac{1}{2} - \frac{1}{16}}{2\frac{1}{6} - 1\frac{3}{8} + \frac{1}{12}} + \frac{6,24 : 0,3 - 15,8}{2,3 \cdot 5 + 2,5} = \frac{\frac{4 + 8 - 1}{16}}{\frac{13}{6} - \frac{11}{8} + \frac{1}{12}} + \frac{\frac{624}{100} : \frac{3}{10} - \frac{158}{10}}{\frac{23}{10} \cdot 5 + \frac{25}{10}} = \frac{\frac{11}{16}}{\frac{52 - 33 + 2}{24}} + \frac{\frac{624}{100} \cdot \frac{10}{3} - \frac{158}{10}}{\frac{23}{2} + \frac{5}{2}} = \frac{\frac{11}{16}}{\frac{21}{24}} + \frac{\frac{208}{10} - \frac{158}{10}}{\frac{28}{2}} = \frac{\frac{11}{16}}{\frac{7}{8}} + \frac{\frac{50}{10}}{14} = \frac{11}{16} \cdot \frac{8}{7} + \frac{5}{14} = \frac{11}{2} \cdot \frac{1}{7} + \frac{5}{14} = \frac{11}{14} + \frac{5}{14} = \frac{16}{14} = \frac{8}{7} \approx 1,14$$

Ответ: $$\frac{8}{7} \approx 1,14$$