[tex]5x^3+4x^2-10x-8=0\\x^2(5x+4)-2(5x+4)=0\\(5x+4)(x^2-2)=0\\5x+4=0\vee x^2-2=0\\5x=-4\ |:5\vee x^2=2\\x=-\frac{4}{5}\vee x=\sqrt2\vee x=-\sqrt2\\x\in\{-\sqrt2,-\frac{4}{5},\sqrt2\}[/tex]
