$\frac{32y^{15}-243}{y^2-3}$

$\left(\frac{2}{3}a+\frac{5}{4}b\right)^{2}$

$-\frac{2}{3}ng^3+\frac{2}{3}g^3n+5g^3$

$\lim_{x\to\frac{\pi\:}{3}}\frac{sen\:\left(x-\frac{\pi\:}{3}\right)}{1\:-2\:cos\:x}$

$sin\left(x\right)+\frac{1}{cos\left(x\right)}$

$40a^3b^3+12a^5b+12ab^5$

$7x^4-28y^4$