4. Выполните действия: а) 2$$\frac{28}{29}$$ - 1$$\frac{18}{29}$$; 6) 12$$\frac{12}{19}$$-3$$\frac{14}{19}$$; в) 10$$\frac{16}{23}$$-9$$\frac{21}{23}$$; г) 10$$\frac{8}{11}$$-2$$\frac{8}{11}$$.

а)

$$2\frac{28}{29} - 1\frac{18}{29} = (2 - 1) + (\frac{28}{29} - \frac{18}{29}) = 1 + \frac{28 - 18}{29} = 1 + \frac{10}{29} = 1\frac{10}{29}$$.

Ответ: $$1\frac{10}{29}$$.

б)

$$12\frac{12}{19} - 3\frac{14}{19} = (12 - 3) + (\frac{12}{19} - \frac{14}{19}) = 9 + (\frac{12 - 14}{19}) = 9 - \frac{2}{19} = 8 + 1 - \frac{2}{19} = 8 + \frac{19}{19} - \frac{2}{19} = 8 + \frac{19 - 2}{19} = 8 + \frac{17}{19} = 8\frac{17}{19}$$.

Ответ: $$8\frac{17}{19}$$.

в)

$$10\frac{16}{23} - 9\frac{21}{23} = (10 - 9) + (\frac{16}{23} - \frac{21}{23}) = 1 + (\frac{16 - 21}{23}) = 1 - \frac{5}{23} = \frac{23}{23} - \frac{5}{23} = \frac{23 - 5}{23} = \frac{18}{23}$$.

Ответ: $$\frac{18}{23}$$.

г)

$$10\frac{8}{11} - 2\frac{8}{11} = (10 - 2) + (\frac{8}{11} - \frac{8}{11}) = 8 + 0 = 8$$.

Ответ: $$8$$.