9+n=-2n

Solution for 9+n=-2n equation:

Simplifying
9 + n = -2n

Solving
9 + n = -2n

Solving for variable 'n'.

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

Add '2n' to each side of the equation.
9 + n + 2n = -2n + 2n

Combine like terms: n + 2n = 3n
9 + 3n = -2n + 2n

Combine like terms: -2n + 2n = 0
9 + 3n = 0

Add '-9' to each side of the equation.
9 + -9 + 3n = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 3n = 0 + -9
3n = 0 + -9

Combine like terms: 0 + -9 = -9
3n = -9

Divide each side by '3'.
n = -3

Simplifying
n = -3