$$\lim_{x\to0}\left(\frac{4^x+\sin\left(x\right)}{x^4}\right)$$

$$73-\left\{23-\left[\frac{15}{\left(-8+5\right)}\right]\right\}-\left\{-1-3\cdot\left[2-5-\left(-4+7\right)\right]\right\}$$

$$\frac{d}{dx}2x^3-8x$$

$$-2a^2x+2ax^2-3ax$$

$$\left(7x+13y\right)\left(7x-13y\right)$$

$$\frac{4u^2\:\left(-2\right)^6\:v^2}{4u\:\left(-2\right)^2\:v^2}$$

$$\left(x+2y+10\right)^2$$