$\frac{\sin\left(x\right)}{\cos\left(y\right)}+\frac{\cos\left(x\right)}{\sin\left(y\right)}=\frac{2\cos\left(x-y\right)}{\sin\left(2y\right)}$

$\:\left(5\:-\:x^2\right)^3$

$9x^2y+3x^2y$

$25a^2+30a+9$

$\int\frac{x+1}{\left(x-3\right)}dx$

$\log\left(x+3\right)-\log\left(3-x\right)=\log\left(2\right)$

$\frac{8x^5y}{y^4}\cdot\frac{5y}{4x^2}$