$\lim_{x\to\infty}\left(\frac{x^2+2x+1}{3x^3+2x^2+x+1}\right)$

$39.5\cdot\left(-\frac{1}{5}\right)$

$\left(5\:+\:12i\right)\:+\:\left[\left(10\:-\:8i\right)\:+\:\left[\left(6\:+\:3i\right)\:-\:\left(7\:+\:2i\right)\right]\right]$

$\frac{6u^2-9u}{3u^2-21u}$

$\left(-2n+-3i\right)^2$

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

$-9x^{-8}y^{-\frac{3}{5}}c^{\frac{4}{7}}$