Question

помогите пожалуйста༎ຶ‿༎ຶ​

Answer 1

Ответ:

5.

$3 \frac{6}{7} \div 2 \frac{4}{7} = \frac{7 \times 3 + 6}{7} \div \frac{7 \times 2 + 4}{7} = \\ \frac{27}{7} \div \frac{18}{7} = \frac{27}{7} \times \frac{7}{18} = \frac{9}{6} = \frac{3}{2} = 1.5$

Ответ: А)

6.

$\frac{27}{49} \div \frac{18}{35} = \frac{27}{49} \times \frac{35}{18} = \frac{15}{10} = 1.5$

Ответ: C)

7.

$(2 \frac{8}{9} \div 1 \frac{4}{9} - \frac{2}{3} ) \times x = 1 \\ (\frac{9 \times 2 + 8}{9} \div \frac{9 \times 1 + 4}{9} - \frac{2}{3} ) \times x = 1 \\ ( \frac{26}{9} \div \frac{13}{9} - \frac{2}{3} ) \times x = 1 \\ ( \frac{26}{9} \times \frac{9}{13} - \frac{2}{3} ) \times x = 1 \\ (2 - \frac{2}{3} ) \times x = 1 \\ (1 \frac{3}{3} - \frac{2}{3} ) \times x = 1 \\ 1 \frac{1}{3} x = 1 \\ \frac{3 \times 1 + 1}{3} x = 1 \\ \frac{4}{3} x = 1 \\ x = 1 \div \frac{4}{3} \\ x = \frac{3}{4} \\ x = 0.75$

Ответ: D)

8.

S = a * b

S = 32 см2

b = 3 1/5 см

$32 = a \times 3 \frac{1}{5} \\ 32 = a \times \frac{5 \times 3 + 1}{5} \\ 32 = a \times \frac{16}{5} \\ a = 32 \div \frac{16}{5} \\ a = 32 \times \frac{5}{16} \\ a = 2 \times 5 \\ a = 10$

Ответ: B)