3x+(x+6)=0

Solution for 3x+(x+6)=0 equation:

Simplifying
3x + (x + 6) = 0

Reorder the terms:
3x + (6 + x) = 0

Remove parenthesis around (6 + x)
3x + 6 + x = 0

Reorder the terms:
6 + 3x + x = 0

Combine like terms: 3x + x = 4x
6 + 4x = 0

Solving
6 + 4x = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-6' to each side of the equation.
6 + -6 + 4x = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 4x = 0 + -6
4x = 0 + -6

Combine like terms: 0 + -6 = -6
4x = -6

Divide each side by '4'.
x = -1.5

Simplifying
x = -1.5