If log (5x - 4) - log (x + 1) = log 4, the value of x is :

1. 6

2. 8

3. 4

4. 12

If log y + 2 log x = 2, the value of y in terms of x is :

1. x² ÷ 100

2. 100 ÷ x²

3. x ÷ 10

4. 10 ÷ x