What is the answer to 3a plus 4 plus b plus 2a plus 5 plus b?

To simplify the expression (3a + 4 + b + 2a + 5 + b), combine like terms. The (a) terms are (3a + 2a = 5a), the (b) terms are (b + b = 2b), and the constant terms are (4 + 5 = 9). Therefore, the simplified expression is (5a + 2b + 9).