$$lnx^{cos4x}$$

$$x^2-8x+16=\left(x-4\right)^2$$

$$\left(2a+25\right)^2$$

$$2+\left(x+3\right)+2+\left(x+3\right)$$

$$\frac{4}{9x}+\:\frac{5}{6x\:}+\frac{7}{18x}$$

$$8v-8y$$

$$\left(2x^3+y\right)\cdot\left(-\frac{1}{4}-xy\right)$$