$\frac{x^2-x-2}{x+2}$

$\int_0^b\left(m\right)dx$

$x^'\cdot x^2=\frac{\left(1+t\right)}{t^2}$

$\frac{x^2-3x-21}{x-7}$

$\int x^3\cdot\left(\frac{1}{\sqrt{255-x^2}}\right)dx$

$-23mn+33abc+17xyz-45abc-18mn-11xyz+48mn-54abc+38xyz-3mn-22abc$

$\left(4a+5b\right)^2\left(4a-5b^2\right)$