$$\lim_{x\to0}\left(\frac{4-4\sqrt{x}}{2+11\sqrt{x}}\right)$$

$$4w^3-484w$$

$$( a ^ { m } + a ^ { h } ) ^ { 2 }$$

$$\frac{d^2}{dx^2}\left(\frac{1}{x^2+5}\right)$$

$$\frac{3x-9}{2x+8}$$

$$tan^2x-8tanx+13=0$$