$$\lim_{x\to\frac{\pi}{2}}\left(\frac{2\sec\left(x\right)+8}{\tan x}\right)$$

$$\left(6x^5y^3+5\right)\left(6x^5y^3-4\right)$$

$$e^x\cdot e$$

$$\int\left(7x+3\right)^{\frac{-1}{2}}dx$$

$$\left(6x^4-3x^3-4x^2+2\right)\left(5x^2-8\right)$$

$$\left(\frac{4}{5}\right)^{\infty}$$

$$2x^2-80x\cdot100$$