$\lim_{x\to6}\left(\frac{x^2-1}{x^2-5x-6}\right)$

$\frac{1}{2}e^u\:\frac{du}{dx}=e^{7x}$

$3\:x\:\frac{1}{24}\:$

$\frac{5v+1}{v^2+2}+\frac{1}{7}+\frac{b^3+7a}{a}$

$\frac{\left(30\right)}{\left(2\right)}$

$\left(\frac{2x^4y^{-2}}{x^4y^4}\right)^2$

$\left(y-3\right)^2-3y\left(2y+5\right)^2+\left(4y-6\right)\left(4y+6\right)$