To simplify this equation, we need to combine like terms on both sides.

On the left side, we have:

3^x - 1 + 3^x + 3^x + 1
=> 3^x + 3^x + 3^x
=> 3(3^x)

On the right side, we have:

12^x - 1 + 12^x
=> 2(12^x)

So the simplified equation becomes:

3(3^x) = 2(12^x)

Now we can simplify further by using the properties of exponents:

3(3^x) = 3^(x+1)
2(12^x) = 2(2^2 3^x) = 22^2 * 3^x = 4(3^x)

Therefore, the simplified equation becomes:

3^(x+1) = 4(3^x)

To solve for x, we can write both sides with the same base:

3^(x+1) = 3^2 * 3^x
3^(x+1) = 9(3^x)

Now, we can equate the exponents:

x + 1 = x + 2
1 = 2

Since 1 does not equal 2, there is no solution to this equation.