Final answer:
To simplify the expression (3z + 3) + (2z - 9), combine like terms by adding the coefficients and then the constants. The simplified expression will be 5z - 6.
Step-by-step explanation:
To simplify the expression (3z + 3) + (2z - 9), we need to combine like terms. Firstly, we can add the coefficients of the z terms: 3z + 2z = 5z. Then, we combine the constant terms: 3 - 9 = -6. Thus, the simplified expression is 5z - 6.
Learn more about Simplifying expressions with like terms