$\frac{4}{x+4}+\frac{6}{2x+3}=\frac{-6}{2x^2+11x+12}$

$\int\left(\left(\frac{-1}{3}\right)\left(2000+x\right)^{-3}\right)dx$

$\tan^2\left(a\right)+\cot^2\left(a\right)+2$

$-239+351$

$-3\left(8-5\right)^2-\left(-7\right)$

$\left(1^9\right)^4$

$\int\left(e^{6x+9}\right)dx$