$x^2-5x=8$

$-25y^3-314y^3$

$\cos\left(\pi-x\right)=-\cos x$

$8x^2y^3\cdot x^4$

$\left(\frac{dy}{dx}\right)y-3\left(\frac{dy}{dx}\right)=-x$

$\log_{13}\left(x\right)=\log_{13}\left(6\right)+\log_{13}\left(5\right)-\log_{13}\left(2\right)$

$\lim_{x\to-1}\left(2x-5\right)$