$\left(-5x^2+a\right)^2$

$x^2-4x-3>0$

$\frac{\cos\:2\left(x\right)}{1-\sin\:2\left(x\right)}=\frac{\cos\:\left(x\right)+\sin\:\left(x\right)}{\cos\:\left(x\right)-\sin\:\left(x\right)}$

$\left(3x^5+2x^2\right)^2$

$x-y^2=0$

$\ln\left(x-4\right)-\ln\left(5-3x\right)+\ln\left(x-2\right)=\ln\left(2\right)$

$\frac{d}{dx}\left(x^x\right)\left(x+2\right)^3\left(5x-9\right)^4$