Помогите решить номер 1.20, 1.21, 1.22

1.20.
$\frac{3.9 \times 0.24 \div \frac{5}{16} }{(4.06 - 2 \frac{1}{2} ) \times 0.8 \times 4 \frac{4}{5} } = \frac{ \frac{39}{10} \times \frac{6}{25} \div \frac{5}{16} }{( \frac{203}{50} - \frac{5}{2} ) \times \frac{4}{5} \times \frac{24}{5} } = \frac{ \frac{39}{10} \times \frac{6}{25} \times \frac{16}{5} }{( \frac{203}{50} - \frac{125}{50} ) \times \frac{4}{5} \times \frac{24}{5} } = \frac{ \frac{39 \times 6 \times 16}{50 \times 25} }{ \frac{78}{50} \times \frac{96}{25} } = \frac{39 \times 6 \times 16}{78 \times 96} = \frac{39}{78} = \frac{1}{2}$

1.21.
$2 - \frac{3 \frac{1}{3} \times 1.9 + 19.5 \div 4 \frac{1}{2} }{ \frac{62}{75} - 0.16 } = 2 - \frac{ \frac{10}{3} \times \frac{19}{10} + \frac{39}{2} \div \frac{9}{2} }{ \frac{62}{75} - \frac{4}{25} } = 2 - \frac{ \frac{19}{3} + \frac{39}{9} }{ \frac{62}{75} - \frac{12}{75} } = 2 - \frac{ \frac{57+39}{9} }{ \frac{50}{75} } = 2 - \frac{96}{9} \div \frac{50}{75} = 2 - \frac{96}{9} \times \frac{75}{50} = 2 - \frac{96}{9} \times \frac{3}{2} = 2 - \frac{ 48\times 1}{3 \times 1} = 2 - 16 = -14$

1.22.
(0,6 + 1/4 + 1/15 + 0,125)*24/(1/3 + 0,4 + 4/15) = (3/5 + 1/4 + 1/15 + 1/8)*24/(1/3 + 2/5 + 4/15) = (72/120 + 30/120 + 8/120 + 15/120)*24/(5/15 + 6/15 + 4/15) = 125/120 * 24 : 15/15 = 25/24 * 24 : 1 = 25