12=r+6+2r

Solution for 12=r+6+2r equation:

Simplifying
12 = r + 6 + 2r

Reorder the terms:
12 = 6 + r + 2r

Combine like terms: r + 2r = 3r
12 = 6 + 3r

Solving
12 = 6 + 3r

Solving for variable 'r'.

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

Add '-3r' to each side of the equation.
12 + -3r = 6 + 3r + -3r

Combine like terms: 3r + -3r = 0
12 + -3r = 6 + 0
12 + -3r = 6

Add '-12' to each side of the equation.
12 + -12 + -3r = 6 + -12

Combine like terms: 12 + -12 = 0
0 + -3r = 6 + -12
-3r = 6 + -12

Combine like terms: 6 + -12 = -6
-3r = -6

Divide each side by '-3'.
r = 2

Simplifying
r = 2