$\lim_{x\to-\infty}\left(\frac{4x}{\sqrt{x^2-1}}\right)$

$a^2-6a-40=0$

$42+42+42+42$

$\int\frac{1}{x\left(ln\left(x\right)\right)^6}dx$

$\frac{x^2-16}{x^2+4x}$

$\int\left(\left(x^2+6\right)\left(18x+x^3+1\right)^5\right)dx$

$\left(1+\sec\left(x\right)\right)\sin\left(x\right)$