$2\times6^{2}$

$\sqrt{x^3}-2\sqrt{4x^3}-x\sqrt{16x}$

$\lim_{x\to0}\left(\frac{e^x-1}{3x^2+5}\right)$

$\left(-6x+8\right)^2$

$\lim_{x\to\infty}\left(\sqrt{x^2-\sin\left(x\right)+1}-\sqrt{x^2-\cos\left(x\right)+1}\right)$

$\frac{dy}{dx}=\frac{x}{y+4},y\left(2\right)=0$

$9x^2-70x+25=0$