$\lim_{x\to\infty}\left(\frac{2x}{3+\frac{6}{x}}\right)$

$\left(i+5j-k^3\right)^2$

$\lim_{x\to-3}\left(\frac{x^2-4x-3}{x^2-9}\right)$

$\int\left(\frac{e^x}{-x^2}\right)dx$

$\left(x^2y^3+6\right)\left(x^2y^3-8\right)$

$x ^ { 5 } - 3 x ^ { 4 } + 4 x ^ { 2 }$

$\int\left(3x\sqrt{x+3}\right)dx$