[m](\frac{2}{5})^{5x+4}=\frac{1}{2}\cdot 10^{\frac{1}{2}}[/m]
[m](\frac{2}{5})^{5x+4}=\frac{1}{2}\cdot 5^{\frac{1}{2}}\cdot 2^{\frac{1}{2}}[/m]
[m](\frac{2}{5})^{5x+4}=(\frac{5}{2})^{\frac{1}{2}}[/m]
[m](\frac{2}{5})^{5x+4}=(\frac{2}{5})^{-\frac{1}{2}}[/m]
[m]5x+4=-\frac{1}{2}[/m]
[m]5x=-\frac{1}{2}-4[/m]
[m]5x=-\frac{9}{2}[/m]
[m]x=-0,9[/m]