Ответ:

[tex]x \div 3.5 = \frac{3}{7} \div 2 \frac{1}{7} [/tex]

[tex]2 \frac{1}{7} x = \frac{3}{7} \times 3.5[/tex]

[tex]2 \frac{1}{7} x = \frac{3}{7} \times 3 \frac{5}{10} = \frac{3}{7} \times \frac{35}{10} = \frac{3}{1} \times \frac{5}{10} = \frac{15}{10} = 1 \frac{5}{10} [/tex]

[tex]2 \frac{1}{7} x = 1 \frac{5}{10} [/tex]

[tex]x = 1 \frac{5}{10} \div 2 \frac{1}{7} = \frac{15}{10} \div \frac{15}{7} = \frac{15}{10} \times \frac{7}{15} = \frac{1}{10} \times \frac{7}{1} = \frac{7}{10} [/tex]

[tex]x = \frac{7}{10} = 0.7[/tex]

[tex]x = 0.7[/tex]