$$\frac{sec^2x}{tan^2x-1}$$

$$[\left(-5\right)^{1}]^{3}$$

$$-5x^3y\left(2x^4-8x^3y^5\right)$$

$$\frac{5w}{3\sqrt{143}}$$

$$\frac{\tan\left(a\right)\cdot\cot\left(a\right)}{1+\tan^2\left(a\right)}\:+\frac{1}{\csc\left(a\right)}$$

$$\frac{1}{x+5}-\frac{1}{x^2+5x}$$

$$sec^2x+csc^2x-tax^2x-cot^2x$$