$\lim_{x\to-6}\left(\frac{\left(x^2-36\right)}{\left|x\right|-6}\right)$

$\left(a-2b-3c\right)^2-\left(3a+2b-3c\right)^2$

$x^2=x+5$

$\int\:\frac{7}{2}sec4x\:tan4xdx$

$-\ln\left(\left(\sec\left(x\right)+\tan\left(x\right)\right)^{\cos\left(x\right)}\right)$

$\frac{dy}{dt}=ctey$

$8^2x^2+y^2$