$$\:\:6.\:\left(\:2\:+\:1\right)-\:-2$$

$$\frac{dy}{dx}=\:\left(3u^2\:-\:6\right)\left(14x\right)$$

$$sec\left(x\right)=\frac{13}{9}$$

$$\int\:\ln\left(1+z^2\right)dz$$

$$m^2+24-10m$$

$$-50\cdot5$$

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