\(VT=\sqrt{7-2\sqrt{10}}-\sqrt{7+2\sqrt{10}}=\sqrt{2-2\sqrt{10}+5}-\sqrt{2+2\sqrt{10}+5}=\sqrt{\left(\sqrt{2}-\sqrt{5}\right)^2}-\sqrt{\left(\sqrt{2}+\sqrt{5}\right)^2}=\left|\sqrt{2}-\sqrt{5}\right|-\left|\sqrt{2}+\sqrt{5}\right|=\sqrt{5}-\sqrt{2}-\sqrt{2}-\sqrt{5}=-2\sqrt{2}=VP\)