$sec^2x-1=\frac{sin^2x}{cos^2x}$

$0.3\left[x-2.1\right]>0.6\left[2x-1.2\right]$

$\left(\frac{1}{x^2-4}-\frac{\sqrt{x-1}}{x^2-4}\right)$

$\lim_{x\to\infty}\left(\frac{\sin\left(x-2\right)}{x-2}\right)$

$3v^2-60v=-141$

$\int\left(\frac{2}{\sqrt{25+16x^2}}\right)dx$

$\left(4a-b\right)\left(3a-b\right)$