Упростите (sqrt(7-sqrt13))-(sqrt(7+sqrt13))

Решите задачу:

$\sqrt{7-\sqrt{13}}-\sqrt{7+\sqrt{13}}=\sqrt{\frac{14-2\sqrt{13}}{2}}-\sqrt{\frac{14+2\sqrt{13}}{2}}=\sqrt{\frac{13-2\sqrt{13}+1}{2}}-\sqrt{\frac{13+2\sqrt{13}+1 }{2}}=\\=\frac{1}{\sqrt{2}}*\sqrt{(\sqrt{13}-1)^{2}}-\frac{1}{\sqrt{2}}*\sqrt{(\sqrt{13}+1)^{2}}=\\=\frac{1}{\sqrt{2}}*(|\sqrt{13}-1|-|\sqrt{13}+1|)=\frac{1}{\sqrt{2}}*(\sqrt{13} -1-\sqrt{13}-1)=\frac{1}{\sqrt{2}}*(-2)=-\sqrt{2}\\\\Otvet:\boxed{-\sqrt{2}}$