$\left(-5x^2-3x\right)-\left(2-4x+6x^2\right)+\left(9x-10\right)$

$\lim_{x\to\infty}\left(x\ln\left(x\right)-\sqrt{x^2+1}\right)$

$\left(\frac{4}{x}-x\right)=\left(\frac{1}{x}+\frac{1}{2}\right)$

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

$\frac{-3x^4+4x^3-6x^2-5}{x^2-2x+4}$

$\lim_{x\to0}\left(\frac{x}{\left(8x^2+5\right)^{\frac{1}{3}}}\right)$

$5x^3\sqrt{x^2}$