$\lim_{x\to3}\left(\frac{2-x}{x-3}\right)$

$6x^2-60x+36=0$

$1+\sec^{2}\left(\theta\right)\left(1-\sin^{2}\left(\theta\right)\right)$

$\left(-1\right)^3-\left(-3\right)^2\left(-2\right)-1\left(1-2\right)^3+3-2\left(-1\right)+4+3\left(-2\right)-\left(2\right)\left(-1\right)$

$2x^3-3x^2+5x-\frac{7}{x-2}$

$r^2+12=7r$

$\int\frac{x^{4}+2x^{2}-x+9}{x^{3}+2x^{4}}dx$