1. Сложение и вычитание дробей с разными знаменателями 2 5 1).+--= 3 8 4 2 4 5). 3+15 8). 3 25 4 9 36 --+= 2). 3). --== 12 8 11 5 16 8 -+- = 7 11 5 -+--= 8 12 6 4). 6 3 -+- 35 10 21 7 7).+--= 53 3 30 9 5 7 9).+-+ -= 96 3 =10). 이다.

1) $$\frac{2}{3} + \frac{5}{8} = \frac{2 \cdot 8}{3 \cdot 8} + \frac{5 \cdot 3}{8 \cdot 3} = \frac{16}{24} + \frac{15}{24} = \frac{16+15}{24} = \frac{31}{24}$$

Ответ: $$\frac{31}{24}$$

2) $$\frac{7}{12} - \frac{3}{8} = \frac{7 \cdot 2}{12 \cdot 2} - \frac{3 \cdot 3}{8 \cdot 3} = \frac{14}{24} - \frac{9}{24} = \frac{14-9}{24} = \frac{5}{24}$$

Ответ: $$\frac{5}{24}$$

3) $$\frac{11}{16} - \frac{5}{8} = \frac{11}{16} - \frac{5 \cdot 2}{8 \cdot 2} = \frac{11}{16} - \frac{10}{16} = \frac{11-10}{16} = \frac{1}{16}$$

Ответ: $$\frac{1}{16}$$

4) $$\frac{6}{35} + \frac{3}{10} = \frac{6 \cdot 2}{35 \cdot 2} + \frac{3 \cdot 7}{10 \cdot 7} = \frac{12}{70} + \frac{21}{70} = \frac{12+21}{70} = \frac{33}{70}$$

Ответ: $$\frac{33}{70}$$

5) $$\frac{4}{5} - \frac{2}{3} + \frac{4}{15} = \frac{4 \cdot 3}{5 \cdot 3} - \frac{2 \cdot 5}{3 \cdot 5} + \frac{4}{15} = \frac{12}{15} - \frac{10}{15} + \frac{4}{15} = \frac{12-10+4}{15} = \frac{6}{15} = \frac{2}{5}$$

Ответ: $$\frac{2}{5}$$

6) $$\frac{7}{8} + \frac{11}{12} - \frac{5}{6} = \frac{7 \cdot 3}{8 \cdot 3} + \frac{11 \cdot 2}{12 \cdot 2} - \frac{5 \cdot 4}{6 \cdot 4} = \frac{21}{24} + \frac{22}{24} - \frac{20}{24} = \frac{21+22-20}{24} = \frac{23}{24}$$

Ответ: $$\frac{23}{24}$$

7) $$\frac{2}{5} + \frac{1}{3} - \frac{7}{30} = \frac{2 \cdot 6}{5 \cdot 6} + \frac{1 \cdot 10}{3 \cdot 10} - \frac{7}{30} = \frac{12}{30} + \frac{10}{30} - \frac{7}{30} = \frac{12+10-7}{30} = \frac{15}{30} = \frac{1}{2}$$

Ответ: $$\frac{1}{2}$$

8) $$\frac{3}{4} - \frac{2}{9} + \frac{5}{36} = \frac{3 \cdot 9}{4 \cdot 9} - \frac{2 \cdot 4}{9 \cdot 4} + \frac{5}{36} = \frac{27}{36} - \frac{8}{36} + \frac{5}{36} = \frac{27-8+5}{36} = \frac{24}{36} = \frac{2}{3}$$

Ответ: $$\frac{2}{3}$$

9) $$\frac{8}{9} - \frac{5}{6} + \frac{1}{3} = \frac{8 \cdot 2}{9 \cdot 2} - \frac{5 \cdot 3}{6 \cdot 3} + \frac{1 \cdot 6}{3 \cdot 6} = \frac{16}{18} - \frac{15}{18} + \frac{6}{18} = \frac{16-15+6}{18} = \frac{7}{18}$$

Ответ: $$\frac{7}{18}$$

10) $$\frac{9}{16} + \frac{5}{6} - \frac{7}{12} = \frac{9 \cdot 3}{16 \cdot 3} + \frac{5 \cdot 8}{6 \cdot 8} - \frac{7 \cdot 4}{12 \cdot 4} = \frac{27}{48} + \frac{40}{48} - \frac{28}{48} = \frac{27+40-28}{48} = \frac{39}{48} = \frac{13}{16}$$

Ответ: $$\frac{13}{16}$$