3+2r+r+9=

Solution for 3+2r+r+9= equation:

Simplifying
3 + 2r + r + 9 = 0

Reorder the terms:
3 + 9 + 2r + r = 0

Combine like terms: 3 + 9 = 12
12 + 2r + r = 0

Combine like terms: 2r + r = 3r
12 + 3r = 0

Solving
12 + 3r = 0

Solving for variable 'r'.

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

Add '-12' to each side of the equation.
12 + -12 + 3r = 0 + -12

Combine like terms: 12 + -12 = 0
0 + 3r = 0 + -12
3r = 0 + -12

Combine like terms: 0 + -12 = -12
3r = -12

Divide each side by '3'.
r = -4

Simplifying
r = -4