$sec^2x=sin^2x$

$4:\left(x-2\right)=2\:\left(x+10\right)$

$\frac{d}{dx}\left(8x^3+9y^3=64\right)$

$\left(3a^3x+y^3\right)^2$

$\frac{d}{dx}\left(3sin\left(x+y\right)+3sin\left(x+z\right)+7sin\left(z+y\right)=0\right)$

$\left(x+3\right)^2+\left(x+4\right)\left(x-3\right)-\left[\left(x+3\right)\left(x-3\right)\right]+\left(x+4\right)\left(x^2-4x+16\right)$

$\frac{4x-6x^4+5}{2x^2-3}$