Answer :

6r - 1 + 6r = 11
    +1            +1
6r + 6r = 12
12r = 12
12      12
r = 1
6r-1+6r=11. Start with the given equation.

12r-1=11. Combine like terms on the left side.

12r=11+1. Add 1 to both sides.

12r=12. Combine like terms on the right side.

r=12/12. Divide both sides by 12 to isolate r.

r=1. Reduce.

Answer: 
So the solution is r=1