Evaluate the expression: (0.7 - 7/20) * 2 2/9 - 0.4 : 1.8

Let's break down the calculation step-by-step:

1. First, calculate the value inside the parentheses:
   • Convert 0.7 to a fraction: $$0.7 = \frac{7}{10}$$
   • Find a common denominator for $$\frac{7}{10}$$ and $$\frac{7}{20}$$. The common denominator is 20.
   • $$\( \frac{7}{10} = \frac{7 \times 2}{10 \times 2} = \frac{14}{20} \)$$
   • Now subtract: $$\( \frac{14}{20} - \frac{7}{20} = \frac{7}{20} \)$$
2. Next, convert the mixed number to an improper fraction:
   • $$2 \frac{2}{9} = \frac{(2 \times 9) + 2}{9} = \frac{18 + 2}{9} = \frac{20}{9}$$
3. Perform the multiplication:
   • $$\( \frac{7}{20} \times \frac{20}{9} \)$$
   • The 20s cancel out: $$\( \frac{7}{\cancel{20}} \times \frac{\cancel{20}}{9} = \frac{7}{9} \)$$
4. Convert 0.4 to a fraction and 1.8 to a fraction:
   • $$0.4 = \frac{4}{10} = \frac{2}{5}$$
   • $$1.8 = \frac{18}{10} = \frac{9}{5}$$
5. Perform the division:
   • $$\( \frac{2}{5} : \frac{9}{5} \)$$
   • Dividing by a fraction is the same as multiplying by its reciprocal: $$\( \frac{2}{5} \times \frac{5}{9} \)$$
   • The 5s cancel out: $$\( \frac{2}{\cancel{5}} \times \frac{\cancel{5}}{9} = \frac{2}{9} \)$$
6. Finally, subtract the results:
   • $$\( \frac{7}{9} - \frac{2}{9} = \frac{5}{9} \)$$

Ответ: 5/9