1) 2 - 3 1 = 3 - 4 1 = 6 4 = 11 -8 40 11 31 13 31 4 7 5 15 1 4 1 2 =

Решение:

1. \( \frac{1}{2} - \frac{1}{3} = \frac{3-2}{6} = \frac{1}{6} \)
2. \( \frac{3}{4} - \frac{3}{8} = \frac{6-3}{8} = \frac{3}{8} \)
3. \( \frac{1}{4} - \frac{1}{6} = \frac{3-2}{12} = \frac{1}{12} \)
4. \( 4 - \frac{5}{11} = \frac{44-5}{11} = \frac{39}{11} \)
5. \( 12\frac{11}{40} - 8 = 4\frac{11}{40} = \frac{160+11}{40} = \frac{171}{40} \)
6. \( 6\frac{11}{31} - \frac{13}{31} = 5\frac{31+11-13}{31} = 5\frac{30}{31} = \frac{5\cdot31+30}{31} = \frac{155+30}{31} = \frac{185}{31} \)
7. \( \frac{4}{5} - \frac{7}{15} = \frac{12-7}{15} = \frac{5}{15} = \frac{1}{3} \)
8. \( 7\frac{1}{4} - 4\frac{1}{2} = 7\frac{1}{4} - 4\frac{2}{4} = 6\frac{4+1}{4} - 4\frac{2}{4} = 6\frac{5}{4} - 4\frac{2}{4} = 2\frac{3}{4} \)

Ответ: $$\frac{1}{6}$$; $$\frac{3}{8}$$; $$\frac{1}{12}$$; $$\frac{39}{11}$$; $$\frac{171}{40}$$; $$\frac{185}{31}$$; $$\frac{1}{3}$$; $$2\frac{3}{4}$$.