$$\lim_{x\to0}\left(\frac{13x^3}{e^{9x}}\right)$$

$$y'=x\left(1-\frac{x}{1000}\right)-60$$

$$3x+5y-2x+3y$$

$$sec\left(2x\right)^2\:+\:2sec\left(2x\right)\:=\:2$$

$$\frac{1}{x}>2$$

$$\int\frac{x^{2}}{e^{3x}}dx$$