5.282 Вычислите значение выражения: a) 14$$\frac{9}{13} - 1$$\frac{5}{13} + 12$$\frac{11}{13}$$; б) 7$$\frac{24}{25}$$ - 3$$\frac{12}{25}$$ - 1$$\frac{7}{25}$$; в) 17$$\frac{7}{40}$$ + 3$$\frac{9}{40}$$ - 1$$\frac{17}{40}$$; г) 23$$\frac{15}{49}$$ - 13$$\frac{19}{49}$$ - 1$$\frac{30}{49}$$

a) $$14\frac{9}{13} - 1\frac{5}{13} + 12\frac{11}{13} = (14-1+12) + (\frac{9}{13} - \frac{5}{13} + \frac{11}{13}) = 25 + \frac{9-5+11}{13} = 25 + \frac{15}{13} = 25 + 1\frac{2}{13} = 26\frac{2}{13}$$ б) $$7\frac{24}{25} - 3\frac{12}{25} - 1\frac{7}{25} = (7-3-1) + (\frac{24}{25} - \frac{12}{25} - \frac{7}{25}) = 3 + \frac{24-12-7}{25} = 3 + \frac{5}{25} = 3\frac{5}{25} = 3\frac{1}{5}$$ в) $$17\frac{7}{40} + 3\frac{9}{40} - 1\frac{17}{40} = (17+3-1) + (\frac{7}{40} + \frac{9}{40} - \frac{17}{40}) = 19 + \frac{7+9-17}{40} = 19 + \frac{-1}{40} = 18\frac{39}{40}$$ г) $$23\frac{15}{49} - 13\frac{19}{49} - 1\frac{30}{49} = (23 - 13 - 1) + (\frac{15}{49} - \frac{19}{49} - \frac{30}{49}) = 9 + \frac{15 - 19 - 30}{49} = 9 + \frac{-34}{49} = 8\frac{15}{49}$$