[tex]1,8+2,(2)-1,2(4)= \\ \\ = \frac{18}{10} +2 \frac{2}{9} -1 \frac{24-2}{90} = \\ \\ = \frac{9}{5} + \frac{20}{9} -1 \frac{22}{90}
= \\ \\ = \frac{9}{5} + \frac{20}{9} - \frac{112}{90} = \\ \\ = \frac{72}{90} + \frac{200}{90} - \frac{112}{90} =\\ \\ = \frac{160}{90} = \frac{16}{9} [/tex]