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

$\lim_{x\to9}\left(\frac{4x-36}{\sqrt{x-9}}\right)$

$\int\frac{2x+5}{\left(x^2+1\right)^2\left(x-3\right)}dx$

$\left(15-10x\right)^2$

$\frac{\cos\theta}{1-\text{sen}^2\theta}=\sec\theta$

$tan\left(x\right)sin2\left(x\right)=2-2cos^2\left(x\right)$

$\frac{1}{1+x}<1$