$$14+7.8$$

$$\int\cot^2\left(x\right)\sec^4\left(x\right)dx$$

$$\left(13n^5n^2+1\right)\left(13n^5n^2-1\right)$$

$$9x^2-12x-45=0$$

$$\lim_{n\to\infty}\left(\frac{1}{\left(\ln\left(n+2\right)\right)^{n+2}}\right)$$

$$\left(6x^4\:+\:3y^3\right)\:\left(6x^4\:-\:3y^3\right)$$

$$\frac{n}{-16}=6$$