$\lim_{x\to-\infty}\left(\frac{x^3}{\sqrt{6x^4-1}}\right)$

$\frac{cot\left(x\right)cos\left(x\right)}{tan\left(-x\right)sin\left(\frac{\pi}{2}-x\right)}$

$\int\left(2x^3e^{-2x}\right)dx$

$5a+18<-27$

$\int\frac{2sec^2\left(t\right)}{tan^2\left(t\right)+14tan\left(t\right)+48}dx$

$9^5\cdot9^2$

$\frac{x^5+x^4+2x+3}{x-1}$