Решение заданий на вычитание и сложение смешанных чисел.

126. Выполните вычитание.

1. $$5\frac{8}{51}-3\frac{5}{17}=5\frac{8}{51}-3\frac{5 \cdot 3}{17 \cdot 3}=5\frac{8}{51}-3\frac{15}{51}=4\frac{59}{51}-3\frac{15}{51}=1\frac{44}{51}$$
2. $$4\frac{2}{9}-1\frac{17}{36}=4\frac{2 \cdot 4}{9 \cdot 4}-1\frac{17}{36}=4\frac{8}{36}-1\frac{17}{36}=3\frac{44}{36}-1\frac{17}{36}=2\frac{27}{36}=2\frac{3}{4}$$
3. $$6\frac{2}{3}-2\frac{6}{7}=6\frac{2 \cdot 7}{3 \cdot 7}-2\frac{6 \cdot 3}{7 \cdot 3}=6\frac{14}{21}-2\frac{18}{21}=5\frac{35}{21}-2\frac{18}{21}=3\frac{17}{21}$$
4. $$3\frac{1}{6}-2\frac{3}{8}=3\frac{1 \cdot 4}{6 \cdot 4}-2\frac{3 \cdot 3}{8 \cdot 3}=3\frac{4}{24}-2\frac{9}{24}=2\frac{28}{24}-2\frac{9}{24}=\frac{19}{24}$$
5. $$9\frac{7}{20}-4\frac{9}{25}=9\frac{7 \cdot 5}{20 \cdot 5}-4\frac{9 \cdot 4}{25 \cdot 4}=9\frac{35}{100}-4\frac{36}{100}=8\frac{135}{100}-4\frac{36}{100}=4\frac{99}{100}$$

123. Найдите сумму.

1. $$3\frac{7}{16}+2\frac{5}{32}=3+\frac{7}{16}+2+\frac{5}{32}=(3+2)+(\frac{7 \cdot 2}{16 \cdot 2}+ \frac{5}{32})=5+(\frac{14}{32}+ \frac{5}{32})=5+\frac{19}{32}=5\frac{19}{32}$$
2. $$1\frac{1}{12}+3\frac{4}{9}=1\frac{1 \cdot 3}{12 \cdot 3}+3\frac{4 \cdot 4}{9 \cdot 4}=1\frac{3}{36}+3\frac{16}{36}=4\frac{19}{36}$$
3. $$4\frac{1}{6}+5\frac{3}{14}+6\frac{2}{21}=4\frac{1 \cdot 7}{6 \cdot 7}+5\frac{3 \cdot 3}{14 \cdot 3}+6\frac{2 \cdot 2}{21 \cdot 2}=4\frac{7}{42}+5\frac{9}{42}+6\frac{4}{42}=15\frac{20}{42}=15\frac{10}{21}$$