$$\frac{4x^2+2}{x-4}$$

$$-2\left(a+2\right)^2$$

$$\left(5m+n\right)\left(m-n\right)$$

$$\left(-\frac{1}{0}-\left(-\frac{1}{-\infty}\right)\right)$$

$$\left(3m+6\right)\cdot\left(3m-6\right)$$

$$1224\cdot259$$

$$\int\frac{x^7}{\left(\sqrt[3]{1+x^4}\right)}dx$$