$$\lim_{x\to\infty}e^{-x}\ln\left(x^4\right)$$

$$\log_x\left(100\right)-\log_x\left(25\right)=2$$

$$10x<0$$

$$\left(y+2\right)^3\left(y+2\right)^2$$

$$\frac{n^3}{3n+7n^3}$$

$$\left(-\sqrt[2]{2x^2+1}\right)\left(\sqrt[2]{2x^2+1}\right)$$