$$x^2-19x-20=0$$

$$4ab^2+\left(6xy^3\right)^2$$

$$3x^2-32x+60$$

$$\cot\left(\theta\:+3\right)$$

$$\frac{sin^3x+cos^2x\cdot\:\:sinx}{cos^2x}$$

$$\lim_{x\to infinity}\left(\frac{16x-3}{16x}\right)^{16x}$$