$\frac{dx}{dt}=\frac{\left(x^2+9\right)}{\left(t^2+36\right)}$

$-x^2-x-2$

$\frac{x-3}{4}-x\le\frac{x-1}{2}-\frac{x-2}{3}$

$\sqrt{0.63246}$

$-\left(+5\right)-11-\left(-13+6\right)$

$\left(x-2\right)y^2dx-x\left(y^2-1\right)dy=0$

$log\:\left(x\:+\:12\right)\:-\:log\:\left(x\:+\:2\right)\:=\:log\:x$