$$\lim_{x\to\infty}\left(\sqrt{x^2+ax}-\sqrt{x^2-bx}\right)$$

$$2x^3-3x$$

$$\ln\left(\sqrt{\left(x^2+12\right)}\right)$$

$$\left(1\right)\left(125x^3\right)\left(1\right)$$

$$5a^{-9}b^{-\frac{5}{6}}c^{-\frac{2}{3}}d^{\frac{4}{5}}$$

$$125l-5$$

$$4x^4+20^6+15^5$$