12+(2k+9)=

Solution for 12+(2k+9)= equation:

Simplifying
12 + (2k + 9) = 0

Reorder the terms:
12 + (9 + 2k) = 0

Remove parenthesis around (9 + 2k)
12 + 9 + 2k = 0

Combine like terms: 12 + 9 = 21
21 + 2k = 0

Solving
21 + 2k = 0

Solving for variable 'k'.

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

Add '-21' to each side of the equation.
21 + -21 + 2k = 0 + -21

Combine like terms: 21 + -21 = 0
0 + 2k = 0 + -21
2k = 0 + -21

Combine like terms: 0 + -21 = -21
2k = -21

Divide each side by '2'.
k = -10.5

Simplifying
k = -10.5