$$5x+18y-13x-14y$$

$$xydx+\left(x+1\right)dy=0$$

$$\frac{t^{11}}{t^2}$$

$$-5-5+4+-4+4$$

$$\lim_{x\to\infty}\left(\frac{4x-3}{4x+2}\right)^{\frac{x^2}{6}}$$

$$\left(5x^2+2\right)\left(x+3\right)$$

$$\frac{2^{3}\cdot5^{-7}\cdot7^{3}}{\left(-2\right)^{-4}\cdot5^{7}\cdot7^{3}}$$