$2x+5\le11-x$

$2x^2-18x+36$

$\left(\frac{7}{\sqrt{5}}-\frac{5}{x}\right)\left(\frac{49}{5}+\frac{7\sqrt{5}}{x}+\frac{25}{x^2}\right)$

$\frac{dy}{dx}-4y=11e^{-x}$

$\frac{d^4y}{dx^4}si\:f\left(x\right)=x^4-2x^3-4x^2-5x+2$

$-\left(x-2y\right)$

$x\:-\:7.8\:-\:2\left(3.4x\:-\:3.7\right)\:+\:6.1x\:$