$4x+\frac{1}{x}$

$\sqrt{4x^2}-9$

$\int_0^{\frac{1}{2}}x\ln\left(x^2\right)dx$

$\left(-k^4+\frac{1}{2}\right)\left(\frac{1}{2}+k^4\right)$

$\frac{dy}{dx}=-2x$

$\left(\frac{\sqrt{25a^2}}{12}+10\right)\left(\frac{\sqrt{25a^2}}{12}+15\right)$