$\tan\left(x\right)=-\frac{1}{2}$

$\int8\sqrt{3-2x-x^2}dx$

$\int\frac{x+2}{\left(x^2-x\right)\left(x^2-1\right)}dx$

$-9x^2y^2-12x^2y^2+5x^2+-15x^2-8+9$

$\frac{2x^2+6}{x^2+4}$

$\frac{\sec\left(a\right)}{\sec\left(a\right)}-\frac{\cos\left(a\right)}{\sec\left(a\right)}$

$\left(\:3a\:-\:2b\:\right)\:+\:\left(\:a\:+\:7b\:\right)\:-\:3\left(-\:2a\:+\:6b\:\right)$