$12\left(0\right)^2e^{-0^2}-6\left(0\right)^{-0^2}$

$\int\frac{5}{2x\sqrt{x^2-25}}dx$

$\lim_{x\to0}\left(\frac{\cos\left(x\right)}{x^2+1}\right)$

$\sqrt{\frac{\sqrt[4]{a^2}\sqrt[3]{b^5}}{c^{-2}d}}$

$x^2+15x=-20$

$\frac{-1.38\cdot\:10^8-9.73\cdot\:10^7}{\left(3\cdot10^8\right)}$

$\frac{\cos\left(a\right)+\tan\left(a\right)}{\cos\left(a\right)\cdot\tan\left(a\right)}=\cot\left(a\right)+\sec\left(a\right)$