$\frac{1}{\cos\left(x\right)}-\tan\left(x\right)=\frac{\cos\left(x\right)}{\sin\left(x\right)+1}$

$\lim_{x\to\infty}\left(\frac{-3x^2-14x+5}{3ln\left(x^4\right)}\right)$

$\left(b+9\right)\left(b-9\right)$

$\int cos\:\left(3t\right)\cdot sen\left(3t\right)dt$

$12+3.18-9$

$\frac{x^3+2x^2-3x-7}{x-2}$

$2x^3-2x-40$