$\left(x+3\right)\left(x+3x+3\right)$

$x^2+32+256$

$3\cdot x=51$

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

$\frac{\left(768x^8-320x^6+28x^2+1\right)}{4x^2+3}$

$\frac{\tan\left(x\right)}{\csc\left(x\right)+\cot\left(x\right)}-\frac{\tan\left(x\right)}{\csc\left(x\right)-\cot\left(x\right)}=-2$

$\int\frac{x^3}{\sqrt{16-x^2}}dx$