$\frac{64a^6-b^9}{4a^2-b^3}$

$\frac{1}{2}\cdot7\left(6\right)$

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

$\lim_{x\to0}\left(\frac{4\sin\left(x\right)}{\sin\left(-2x\right)}\right)$

$\lim_{x\to\infty}\left(x^2-4x-x\right)$

$11\left(-7+3\right)$

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