[tex]x - nr.[/tex]
[tex] \frac{2}{5} \times x + \frac{30}{100} \times x = x - \frac{1}{5} [/tex]
[tex] \frac{2x}{5} + \frac{30x}{100 } = x - \frac{1}{5} [/tex]
[tex] \frac{2x}{5} + \frac{3x}{10} = x - \frac{1}{5} \: | \times 10[/tex]
[tex] 2 \times 2x + 3x = 10x - 2[/tex]
[tex]4x + 3x = 10x - 2[/tex]
[tex]7x = 10x - 2[/tex]
[tex]7x - 10x = - 2[/tex]
[tex] - 3x = - 2 \: | \times ( - 1)[/tex]
[tex]3x = 2[/tex]
[tex]x = \frac{2}{3} [/tex]
