$\int_2^4\left(\frac{2}{x\sqrt{x^2-4}}\right)dx$

$2x^2-x-28$

$k^2-2k-48$

$x''\left(t\right)-4x'\left(t\right)+4x\left(t\right)=30t^2e^2t$

$cos^2x\cdot\frac{dy}{dx}=3y^2$

$1-\left\{4-\left[-2+\left(5-1-9\right)-1\right]+2\right\}+3$

$f\left(x\right)=\left(x^2-9\right)\left(16\right)$