Start by distributing 2 inside the parentheses holding 3b + 1. After distributing you will have: 12b + 9 = 6b + 9 + 6b + 2.
Now combine like terms on the right side of the equation, and after doing so you will have: 12b + 9 = 12b + 11.
Subtract 12b from both sides and now you have a weird looking equation (no variable!): 9 = 11.
Determine if this is a true or false statement; 9 = 11 is a false statement so that means that your answer is No solution.
