$1.6\:x\:10^3$

$\frac{dz}{dx}\:e^z=xyz$

$1000+200x\le1800+110x$

$\left(-9x^2y\right)\cdot\left(4x^2z^2\right)$

$\ln\left(-x\right)=\ln\left(x^2-6\right)$

$\:\left(5-8-9\right)+38-2\left[3+4-5\right]-1$

$\lim_{x\to\frac{\pi}{2}}\left(\frac{\tan\left(x\right)}{\tan\left(4x\right)}\right)$