$\frac{18x^{2}y+27x^{2}y-45x^{3}y^{5}}{9xy}$

$f\left(x\right)=x^3-2x^2-15x$

$\tan\left(u\right)\cdot\csc\left(u\right)^2-\cot\left(x\right)\cdot\sec\left(u\right)^2$

$2^2-3^3+11$

$\lim_{x\to\frac{\pi}{2}}\left(\frac{\ln\left(\sin^2\left(x\right)\right)}{\left(\frac{\pi}{2}-x\right)^2}\right)$

$\:\left(\frac{x}{3}+\frac{2}{y}\right)^4$

$-3+4i^2\frac{3}{2}$