(4) Which statements are true about the expression \( y+9 \) ? Choose ALL that apply. \begin{tabular}{|l|}\hline (4) \( ) \) The letter \( y \) is a variable. \\ \hline (4) The letter \( y \) is a constant. \\ \hline The letter \( y \) is a term. \\ (4) The number 9 is a constant. \\ (4) The number 9 is a variable. \\ (5) The number 9 is a term. \\ \hline\end{tabular}

The expression \( y + 9 \) includes both a variable and a constant. The letter \( y \) is indeed a variable because it can represent different values, whereas the number 9 is a constant since it does not change. Additionally, both \( y \) and 9 are considered terms in the expression. Therefore, the true statements are: - The letter \( y \) is a variable. - The number 9 is a constant. - The letter \( y \) is a term. - The number 9 is a term. The statement that \( y \) is a constant and that 9 is a variable is false.