$$\lim_{x\to\infty}\:\frac{\left(x^2-3x+6\right)}{x-2}$$

$$3^{3x}=9^{x+1}$$

$$7x^4\left(x^2-4x\right)$$

$$f\left(x\right)=\frac{x^2-x}{x-1}$$

$$12\int sen\ln\left(x\right)dx$$

$$\log_{13}\left(x\right)=\log_{13}\left(6\right)+\log_{13}\left(5\right)-\log_{13}\left(2\right)$$