1)
$$4\frac{2}{3} \cdot 6 - 1\frac{23}{12} \cdot 3\frac{1}{13} + 2\frac{1}{8} - 1\frac{29}{51} = \frac{14}{3} \cdot 6 - \frac{35}{12} \cdot \frac{40}{13} + \frac{17}{8} - \frac{80}{51} = $$
$$= 14 \cdot 2 - \frac{35}{3} \cdot \frac{10}{13} + \frac{17}{8} - \frac{80}{51} = 28 - \frac{350}{39} + \frac{17}{8} - \frac{80}{51} = 28 - \frac{350 \cdot 8}{39 \cdot 8} + \frac{17 \cdot 39}{8 \cdot 39} - \frac{80 \cdot8}{51\cdot 8} =$$
$$= 28 - \frac{2800}{312} + \frac{663}{312} - \frac{640}{408} = 28 - \frac{2137}{312} - \frac{160}{102} = 28 - \frac{2137}{312} - \frac{80}{51}= 28 - 6\frac{205}{312} - 1\frac{29}{51}=$$
$$= 28 - 6\frac{205}{312} - 1\frac{29}{51}= 21 - \frac{205}{312} - \frac{29}{51} = 21 - \frac{205 \cdot 17}{312 \cdot 17} - \frac{29 \cdot 104}{51 \cdot 104} =$$
$$= 21 - \frac{3485}{5304} - \frac{3016}{5304}= 21 - \frac{6501}{5304}= 21- 1\frac{1197}{5304} = 19\frac{4107}{5304}$$
Ответ: $$19\frac{4107}{5304}$$