$$2\csc^2x-\csc x=1$$

$$\frac{d^2y}{dx^2}=\frac{2}{3}cos8x-\frac{1}{6}sen8x$$

$$\frac{2}{3}\left(6x+3\right)=4x-2$$

$$\left(5x-2\right)\left(6x^2-3x+2\right)$$

$$4x+3+4x+3+4x+3$$

$$\frac{x^4+2x^3-10}{x-3}$$

$$26\cdot112$$