$$x-19=28$$

$$\log\left(x+1\right)+\log x=\log3$$

$$\left(n-4\right)\left(n-5\right)$$

$$\frac{2x+5}{-4x+8}$$

$$1+\tan^2\left(b\right)$$

$$\left(\frac{16}{8}\right)^2$$

$$\frac{a^6.\left(a^2\right)^3.\left(a^4\right)^2}{a.a^3.\left(a^2\right)^3}$$