$\frac{dt}{dr}=\frac{c}{k}\cdot\frac{1}{r}$

$\sqrt{a}+\sqrt{3b}$

$3x\left(x-2\right)+x^2$

$\left(1-3m\right)^3$

$\frac{d}{dx}\left(\ln\left(x^6-5\right)\right)$

$2\sin\left(x\right)\cos\left(x\right)+2\sin\left(2x\right)=0$

$-\int\left(4x^2\cdot\sqrt{1-2x}\right)dx$