$dy=\frac{6x-12}{x^2}dx$

$x^8-4\sqrt{2}x^6-4x^4+8x^4+8\sqrt{2}x^2+4$

$x^2-18+c=0$

$\frac{d}{dx}5x^4\sqrt{3x-1}$

$\frac{tan\left(x\right)-1}{tan\left(x\right)+1}=\frac{\sec^2\left(x\right)-2}{\sec^2\left(x\right)+2\tan\left(x\right)}$

$\cos a\cdot\cos b+\sin a\cdot\sin b$

$\left(-1\right)\left(2\right)\left(-6\right)$