$-7+3\cdot\left(-8\right)$

$\frac{1}{a-2}+\frac{1}{a^2-7a-10}=\frac{6}{a-2}$

$7m-3n+\left(4m+\left(3m-4n\right)-\left(5m-2n\right)+6m\right)-8m$

$\sqrt{2025}$

$4k^2+2k+2$

$\frac{1-sec\left(-\theta\right)}{sec\left(-\theta\right)}$

$\int\left(\tan\left(\frac{x}{18}\right)^5\right)dx$