$x^3+x^2-6\cdot x^2+x-1$

$2\csc\left(2x+\frac{\pi}{6}\right)$

$\frac{x^3+x^2-1}{x^2+x}$

$\left(x+3\right)^2-\left(x-3\right)^2-3\left(2x-1\right)$

$\int\frac{2x+3}{\left(x-1\right)x\left(x+2\right)}dx$

$\lim_{x\to0}\left(\ln\left(1+2x\right)\right)$

$2a-3b^24a-5b^2$