If 4 × 2^{x + 3} = 8^{x + 1}, then 2^x =

1. 1

2. 2

3. 4

4. 8

If 2^{x + 3} + 2^{x + 1} = 320, then x =

1. 2

2. 3

3. 4

4. 5

If (2⁵ + 0.125)² - (2⁵ - 0.125)² = 2^x, then the value of x is :

1. 2

2. 3

3. 4

4. 5