n+n+2+n+4+n+6+n+8=-9

Solution for n+n+2+n+4+n+6+n+8=-9 equation:

Simplifying
n + n + 2 + n + 4 + n + 6 + n + 8 = -9

Reorder the terms:
2 + 4 + 6 + 8 + n + n + n + n + n = -9

Combine like terms: 2 + 4 = 6
6 + 6 + 8 + n + n + n + n + n = -9

Combine like terms: 6 + 6 = 12
12 + 8 + n + n + n + n + n = -9

Combine like terms: 12 + 8 = 20
20 + n + n + n + n + n = -9

Combine like terms: n + n = 2n
20 + 2n + n + n + n = -9

Combine like terms: 2n + n = 3n
20 + 3n + n + n = -9

Combine like terms: 3n + n = 4n
20 + 4n + n = -9

Combine like terms: 4n + n = 5n
20 + 5n = -9

Solving
20 + 5n = -9

Solving for variable 'n'.

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

Add '-20' to each side of the equation.
20 + -20 + 5n = -9 + -20

Combine like terms: 20 + -20 = 0
0 + 5n = -9 + -20
5n = -9 + -20

Combine like terms: -9 + -20 = -29
5n = -29

Divide each side by '5'.
n = -5.8

Simplifying
n = -5.8