$\int\frac{3}{\left(x-3\right)^3}dx$

$\lim_{x\to0}\left(\frac{\sqrt{9-x^2}-3}{x}\right)$

$\lim_{x\to\infty}\left(\frac{ln\left(x^7\right)}{9x}\right)$

$x^{2\:}-\:x=-2$

$6tan^2-5tanx-25$

$2a+b;\:a=1;\:b=2$

$\frac{6\sin\left(-x\right)\cos\left(-x\right)}{\cos^2\left(x\right)-\sin^2\left(x\right)}$