1) Выполните действия: A) 12-5 +4 13 13 13 919+ Б) 9 13 + (818-315) 7 B) 5+1 11 Г) 7-3 5 9 Д) 6-42 11 11 19 E) 10-(4+3)

1) Выполните действия:

A) $$ \frac{12}{13}-\frac{5}{13}+\frac{4}{13} = \frac{12-5+4}{13} = \frac{11}{13} $$.

Ответ: $$\frac{11}{13}$$

Б) $$9\frac{19}{13}+(8\frac{18}{19}-3\frac{15}{19}) = 9\frac{19}{13}+((8-3)+(\frac{18}{19}-\frac{15}{19})) = 9\frac{19}{13} + 5\frac{3}{19} = 9 + \frac{19}{13} + 5 + \frac{3}{19} = 14 + \frac{19}{13} + \frac{3}{19} = 14 + \frac{19 \cdot 19 + 3 \cdot 13}{13 \cdot 19} = 14 + \frac{361 + 39}{247} = 14 + \frac{400}{247} = 14 + 1\frac{153}{247} = 15\frac{153}{247}$$.

Ответ: $$15\frac{153}{247}$$

B) $$5\frac{7}{11}+1\frac{5}{11} = (5+1) + (\frac{7}{11} + \frac{5}{11}) = 6 + \frac{12}{11} = 6 + 1\frac{1}{11} = 7\frac{1}{11}$$.

Ответ: $$7\frac{1}{11}$$

Г) $$7\frac{5}{9}-3\frac{5}{9} = (7-3)+(\frac{5}{9} - \frac{5}{9}) = 4 + 0 = 4 $$.

Ответ: $$4$$

Д) $$6\frac{5}{11}-4\frac{9}{11} = (6-4) + (\frac{5}{11} - \frac{9}{11}) = 2 + (\frac{5-9}{11}) = 2 - \frac{4}{11} = 1\frac{11}{11} - \frac{4}{11} = 1\frac{7}{11}$$.

Ответ: $$1\frac{7}{11}$$

E) $$10\frac{4}{21}-(4\frac{10}{21}+3\frac{19}{21}) = 10\frac{4}{21}-((4+3)+(\frac{10}{21}+\frac{19}{21})) = 10\frac{4}{21} - (7 + \frac{29}{21}) = 10\frac{4}{21} - 7\frac{29}{21} = (10-7) + (\frac{4}{21} - \frac{29}{21}) = 3 + (\frac{4-29}{21}) = 3 - \frac{25}{21} = 3 - 1\frac{4}{21} = 2\frac{21}{21} - 1\frac{4}{21} = 1\frac{17}{21}$$.

Ответ: $$1\frac{17}{21}$$