1) x^2 + 6x + 5 = 0

Factorizing the quadratic equation, we get:

(x + 5)(x + 1) = 0

Therefore, the solutions are x = -5 or x = -1.

2) 12x^2 = 0

Dividing by 12 on both sides, we get:

x^2 = 0

Taking the square root on both sides, we get:

x = 0

Therefore, the solution is x = 0.