$$\frac{4}{x+4}+\frac{1}{x-4}=\frac{13}{x^2-16}$$

$$x^2-6x+2x-6$$

$$4y=-32$$

$$\frac{d}{dx}ln\:\frac{x^2+5x+4}{x^9}$$

$$\sec\left(x\right)-\sec\left(x\right)\sin^2\left(x\right)=\sin\left(x\right)$$

$$x^2+26x+88$$

$$\int\left(\frac{1}{9-\sqrt{y}}\right)dy$$