[tex](( - \frac { 3}{5} )\times 2.5 - \frac{5}{6} ) \div \frac{20}{42} + 11 + \frac{1}{10} \times \sqrt{81} = [/tex]
[tex](( - \frac { 3}{5}) \times \frac{25}{10} - \frac{5}{6} ) \div \frac{10}{21} + 11 + \frac{1}{10} \times 9 = [/tex]
[tex]( - \frac { 3 \times 25}{5 \times 10} - \frac{5}{6} ) \times \frac{21}{10} + 11 + \frac{9}{10} = [/tex]
[tex]( - \frac { 3 \times 1}{1 \times 2} - \frac{5}{6} ) \times \frac{21}{10} + 11 + \frac{9}{10} = [/tex]
[tex]( - \frac { 3 }{ 2} - \frac{5}{6} ) \times \frac{21}{10} + 11 + \frac{9}{10} = [/tex]
[tex]( - \frac { 9}{6} - \frac{5}{6} ) \times \frac{21}{10} + 11 + \frac{9}{10} = [/tex]
[tex]( - \frac{14}{6} ) \times \frac{21}{10} + 11 + \frac{9}{10} = [/tex]
[tex] - \frac{7 \times 7}{1 \times 10} + 11 + \frac{9}{10} = [/tex]
[tex] - \frac{49}{ 10} + 11 + \frac{9}{10} = [/tex]
[tex] - 4.9 + 11 + 0.9 = \\ 6.1 + 0.9 = 7[/tex]
