[tex]\it\Big( \dfrac{2x^2}{x^2-5}\Big)'=\dfrac{(2x^2)'(x^2-5)-2x^2(x^2-5)'}{(x^2-5)^2}=\dfrac{4x(x^2-5)-2x^2\cdot2x}{(x^2-5)^2}=\\ \\ \\ =\dfrac{4x^3-20x-4x^3}{(x^2-5)^2}=\dfrac{20x}{(x^2-5)^2}[/tex]
