$2x^2-4x\:-\:1=0$

$\frac{1-\cos a}{\sin a}-\frac{\sin a}{1+\cos a}=0$

$\cos\left(y\right)\frac{dy}{dt}=\frac{-t\sin\left(y\right)}{1+t^2}$

$\frac{\sin\:\left(5x\right)-\sin\left(9x\right)}{\cos\left(5x\right)+\cos\left(9x\right)}=-\tan\left(2x\right)$

$=0\cdot\:\ln\:\left(t\right)+4t$

$6m^2+11m+3$

$\frac{64y^3+x^3}{4y+x}$