Solve for x :

3(2^x + 1) - 2^{x + 2} + 5 = 0

Solve for x :

9^{x + 2} = 720 + 9^x

(-2)^-1 ÷ (-2)^-4 is equal to:

1. 8

2. $\dfrac{1}{8}$

3. -8

4. -$\dfrac{1}{8}$

If $\dfrac{a}{b} = \dfrac{2}{3} ÷ \Big(-\dfrac{2}{3}\Big)^0; \text{then} \Big(\dfrac{a}{b}\Big)^{-2}$ is equal to:

1. $\dfrac{4}{9}$

2. $-\dfrac{4}{9}$

3. $\dfrac{9}{4}$

4. $-\dfrac{9}{4}$