[tex](x\sqrt2-3)^2=5\\
2x^2-6x\sqrt2+9=5\\
2x^2-6x\sqrt2+4=0\\
\Delta=72-32=40=\ \textgreater \ \sqrt{\Delta}=2\sqrt{10 }\\
x_1=\frac{6\sqrt2-2\sqrt{10}}{4}\Rightarrow
x_1=\frac{3\sqrt2-\sqrt{10}}{2} \\
x_2=\frac{6\sqrt2+2\sqrt{10}}{4}\Rightarrow x_2=\frac{3\sqrt2+\sqrt{10}}{2}[/tex]