8√2+4×√5-4×2√2-3√5=
8√2+4√5-8√2-3√5=
4√5-3√5=√5
[tex]\it8\sqrt2+4(\sqrt5-2\sqrt2)-3\sqrt5=8\sqrt2+4\sqrt5-8\sqrt2-3\sqrt5=\sqrt5[/tex]