[tex]10x {}^{2} = 0.4 - 3x[/tex]

[tex]10x {}^{2} + 3x - 0.4[/tex]

[tex]d = 3 {}^{2} - 4 \times 10 \times ( - 0.4) = 25[/tex]

[tex]x1 = \frac{ - 3 + 5}{20} = \frac{2}{20} = \frac{1}{10} [/tex]

[tex]x2 = \frac{ - 3 - 5}{20} = \frac{ - 8}{20} = - \frac{2}{5} [/tex]

Ответ: x1=1/10 x2=-2/5