[tex]a) \frac{5}{12}+ \frac{5}{24}= \frac{10+5}{24}= \frac{15}{24} \\ \\ b)\frac{26}{21}+ \frac{13}{14}= \frac{26\cdot2+13\cdot3}{42}= \frac{52+39}{42} = \frac{92}{42}= \frac{46}{21}=2 \frac{4}{21} \\ \\ c) \frac{4}{15}+ \frac{3}{20}= \frac{16+9}{60}= \frac{25}{60}= \frac{5}{12} \\ \\ d) \frac{5}{24}+ \frac{1}{12}+ \frac{3}{8} = \frac{5+2+9}{24}= \frac{16}{24}= \frac{2}{3} \\ \\ e) \frac{7}{30} - \frac{3}{20}= \frac{7\cdot2-3\cdot3}{60} = \frac{14-9}{60}= \frac{5}{60}= \frac{1}{12} [/tex]
[tex]f)\frac{8}{15} - \frac{9}{20}= \frac{4\cdot8-3\cdot9}{60} = \frac{32-27}{60}= \frac{5}{60}= \frac{1}{12} [/tex]
[tex]g)\frac{8}{21} - \frac{4}{32}= \frac{8\cdot5-4\cdot3}{105} = \frac{40-12}{105}= \frac{28}{105}= \frac{4}{15} [/tex]
[tex] d) \frac{7}{6}- \frac{3}{4}- \frac{1}{12} = \frac{7\cdot2-3\cdot3-1}{12}= \frac{14-9-1}{12}= \frac{4}{12}= \frac{1}{3} \\ \\[/tex]
