[tex]5x^6+10x^5-4x^4-8x^3=0\\x^3\left(x+2\right)\left(\sqrt{5}x+2\right)\left(\sqrt{5}x-2\right)=0\\\\x=0,\:x=-2,\:x=-\cfrac{2\sqrt{5}}{5},\:x=\frac{2\sqrt{5}}{5}[/tex]
