You've uploaded a photo that contains mathematical expressions with instructions to simplify or rewrite these expressions. Let's tackle each one:

2. Rewrite the following positive integers:

a. $(-2x)^3$ b. $(-2x^2)^3$ c. $-5a^4$ d. $\frac{3b^2}{2x^3}$ e. $\left( \frac{xy}{z^3x^2} \right)^2$

3. Simplify the following expressions to positive powers:

a. $\left( \frac{625 a^{12}b^6c^2}{5a^4b^5} \right)^2$ b. $\left( \frac{3x^2y^3}{24b^4} \right)^3 \cdot \left( \frac{16a^6b^6}{27x^3y} \right)^2$ c. $\frac{a^7 + b^7}{a^4 + b^2}$ d. $\frac{2^3 + 3^2}{2^2 + 3^3}$

Solutions:

2a. $(-2x)^3$: $= -8x^3$

2b. $(-2x^2)^3$: $= -8x^6$

2c. $-5a^4$: $= -5a^4 \quad (\text{Already simplified})$

2d. $\frac{3b^2}{2x^3}$: $= \frac{3b^2}{2x^3} \quad (\text{Already simplified})$

**