If 3^{x + 1} = 9^{x - 2}, the value of x is :

1. -5

2. 5

3. 0

4. 3

If $\sqrt{\dfrac{a}{b}} = \Big(\dfrac{b}{a}\Big)^{1 - 2x}$, the value of x is :

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

2. $\dfrac{3}{5}$

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

4. $-\dfrac{3}{5}$

Solve for x :

2^{5x - 1} = 4 × 2^{3x + 1}

Solve for x :

3^{4x + 1} = (27)^{x + 1}