$$\lim_{x\to-9}\left(\frac{x^3-729}{x^2-9x}\right)$$

$$\frac{dy}{dx}=\frac{2y}{x+4}$$

$$7x-x^3$$

$$\int4cos\left(x\right)cos^5\left(sinx\right)dx$$

$$\left(8\right)\cdot\left(-4\right)\cdot\left(-7\right)$$

$$\sqrt[3]{x^3y^3}$$

$$\left(5b+3\right)\left(7b-3\right)$$