Ответ:

[tex]1)(1 \frac{4}{9} + 2 \frac{5}{6} - 2 \frac{3}{4} ) \div (2 \frac{1}{2} - \frac{1}{4} ) = (1 \frac{16}{36} + 2 \frac{30}{36} - 2 \frac{27}{36} ) \div (2 \frac{2}{4} - \frac{1}{4} ) = \frac{55 \times 4}{36 \times 9} = \frac{55}{81} [/tex]

[tex]2)(3.6 - 1 \frac{2}{3} ) \div (4 \frac{1}{15} - 2 \frac{7}{9} ) = ( \frac{54}{15} - \frac{25}{15} ) \div (4 \frac{3}{45} - 2 \frac{35}{45} ) = \frac{29}{15} \div \frac{58}{45} = \frac{29 \times 45}{15 \times 58} = \frac{3}{2} = 1.5[/tex]