$$19^2y^2$$

$$3abc-5ac+2bc$$

$$\lim_{x\to\infty}\left(-2x+2\right)$$

$$20x^3-20x^2$$

$$\left(y^9+3\right)\left(y^9-13\right)$$

$$2\:\left(x\:+\:6\right)\:>x\:+\:20$$

$$\frac{dx}{dt}+x=e^{3t},x\left(0\right)=1$$