$$x^2+4x+5=0$$

$$\frac{13r^7}{39r^6}$$

$$3z^2-9z+27xz-81x$$

$$\left(\frac{x}{\sqrt{2}y}\right)^2$$

$$\lim_{x\to0}\left(\frac{sin^2\left(x\right)sin\left(\frac{1}{x}\right)}{x\cdot sin\left(\frac{1}{2x}\right)}\right)$$

$$\int\frac{x-3}{\left(x^2+4\right)\left(x-1\right)}dx$$

$$\lim_{x\to0}\left(x^{x\cdot\ln\left(x\right)}\right)$$