[tex]5 \frac{9}{14} - 2 \frac{3}{7} + 6.7 = 5 \frac{9}{14} - 2 \frac{6}{14} + 6.7 = 3 \frac{3}{14} + 6 \frac{7}{10} =3 \frac{15}{70} + 6 \frac{49}{70} = 9 \frac{64}{70} =9 \frac{32}{35} \\ \\
9 \frac{1}{4} \times 8 - 1 \frac{2}{3} \times 5 \frac{1}{2} - 2 \frac{4 }{5} \times 2 \frac{11}{12} = 56 \frac{2}{3} \\ 1) \: 9 \frac{1}{4} \times 8 = \frac{37 \times 8}{4} = 37 \times 2 = 74 \\ 2) \: 1 \frac{2}{3} \times 5 \frac{1}{2} = \frac{5 \times 11}{3 \times 2} = \frac{55}{6} = 9 \frac{1}{6} \\ 3) \: 2 \frac{4}{5} \times 2 \frac{11}{12} = \frac{14 \times 35}{5 \times 12} = \frac{7 \times 7}{6} = \frac{49}{6} = 8 \frac{1}{6} \\ 4) \: 74 - 9 \frac{1}{6} - 8 \frac{1}{6} = 56 \frac{4}{6} =56 \frac{2}{3} [/tex]