Question

(x√2-3) totul la a doua este egala cu 5

Answer 1

[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]