$\lim_{x\to3}\left(\frac{\left(x^2-9\right)}{x^2-6x+9}\right)$

$\int\frac{6x-1}{x^3\left(2x+1\right)}dx$

$\frac{27a^3b^2}{3ab^2}$

$-35\::\:\:x\:\:=\:5$

$2\sin\left(x\right)=-\cos\left(x\right)^2+1$

$2\cos\left(\frac{5\pi}{4}\right)-\sec\left(\frac{\pi}{4}\right)$

$7y+2x+\left(7x+2y\right)y'\:=0$