Answer:
Simplifying
6r + r + -5r = 0
Combine like terms: 6r + r = 7r
7r + -5r = 0
Combine like terms: 7r + -5r = 2r
2r = 0
Solving
2r = 0
Solving for variable 'r'.
Move all terms containing r to the left, all other terms to the right.
Divide each side by '2'.
r = 0
Simplifying
r = 0