$\int-7x\sqrt{x+4}dx$

$\csc^2\left(x\right)\sin\left(2x\right)$

$-6\sec\left(\theta\right)+\frac{10\sqrt{3}}{3}=-11\sec\left(\theta\right)+\frac{20\sqrt{3}}{3}$

$a+\left(+b-c\right)+2a-\left(+a+b\right)$

$5\:.\:9^2$

$\frac{d^2}{dx^2}\left(x^2-xy+y^2-3y\right)$

$-\frac{48c^2d^4}{-8cd}$