$$x^5\cdot\left(x^4\cdot x^{-7}\right)$$

$$\frac{x-2}{4}=-3$$

$$81x^4y^6-25z^8$$

$$\frac{-3}{5}=\frac{1}{5}$$

$$\frac{x^3+x-2}{x+2}$$

$$\left(2a^5+b^6\right)\left(2a^5-b^6\right)$$

$$\lim_{x\to1}\left(\frac{x^3+8}{x+2}\right)$$