Ответ:

х = 6

Пошаговое объяснение:

[tex]7 - (x - \frac{1}{10} ) - \frac{3}{7} = \frac{31}{35} - \frac{3}{14} [/tex]

[tex]7 - x + \frac{1}{10} - \frac{3}{7} = \frac{31}{35} - \frac{3}{14} [/tex]

[tex]7 - x + \frac{1}{10} - \frac{3}{7} = \frac{62}{70} - \frac{15}{70} [/tex]

[tex]7 - x + \frac{1}{10} - \frac{3}{7} = \frac{47}{70} [/tex]

[tex]7 - x + \frac{1}{10} = \frac{47}{70} + \frac{3}{7} [/tex]

[tex]7 - x + \frac{1}{10} = \frac{47}{70} + \frac{30}{70} [/tex]

[tex]7 - x + \frac{1}{10} = \frac{77}{70} [/tex]

[tex]7 - x + \frac{1}{10} = \frac{11}{10} [/tex]

[tex]7 - x = \frac{11}{10} - \frac{1}{10} [/tex]

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

[tex]7 - x = 1[/tex]

[tex] - x = 1 - 7[/tex]

[tex] - x = - 6 [/tex]

[tex]x = 6[/tex]