$x^2+y^2-16x=0$

$12=5x+27$

$\frac{3x}{4x+2}=\frac{x+2}{x}$

$3.\:\left[2+\:\left(8-9\right)\right]$

$\frac{dy}{dx}\left(x^2=\left(\frac{2x+3y}{2x-3y}\right)\right)$

$\log\left(x\right)+\log\left(x+1\right)=\log\left(2\right)$

$-12a\left(m-n+1\right)\:+\:\left(-m+n-1\right)\:+m\:\left(6m+6n+6\right)$