[latex]4 x^{2} -0,09=0[/latex]

[latex]4x^2-0,09=0 \\ 4x^2= \frac{9}{100} \\ x^2= \frac{9}{400} \\ x_{1} = \frac{3}{20} \\ x_{2}=- \frac{3}{20} [/latex]