$$\int4cos\left(\frac{x}{2}+8\right)dx$$

$$\frac{-x^2+x-1}{3-x}$$

$$356+\left(-9\right)$$

$$4^{x+1}+4^x=80$$

$$4\cdot3+7\cdot2$$

$$2xy\:+\:3y\:-\:2x\:+\:4y\:+\:3y\:+\:5x\:-\:6xy\:$$

$$\frac{dy}{dx}=\frac{y}{x}-\frac{y^2}{x}$$