Answer:
x = -2
Explanation:

First, try to factor out a common factor from every term.
The coefficients are 3, 12, and 12.
The GCF (greatest common factor) of 3, 12, and 12 is 3, so factor out a 3 from all terms.

Now divide both sides by 3.

You have a quadratic trinomial of the form x^2 + ax + b.
To factor it, you need to find two numbers that multiply to b and add to a. Call these two numbers p and q.
Then the factorization is (x + p)(x + q).
In your case, you have

In this case, a = 4 and b = 4.
You need two numbers that multiply to 4 and add to 4.
The numbers are 2 and 2.
Then the factorization is
Now set each factor equal to zero and solve for x.
x + 2 = 0 or x + 2 = 0
x = -2 or x = -2
Answer: x = -2