Simplify the following expression: \[ 15 c+3(9+4 c) \]

To simplify the expression \( 15c + 3(9 + 4c) \), we start by distributing the 3 in the second term: \[ 15c + 3 \cdot 9 + 3 \cdot 4c \] This gives us: \[ 15c + 27 + 12c \] Next, we combine like terms. The terms \( 15c \) and \( 12c \) can be combined together: \[ (15c + 12c) + 27 = 27c + 27 \] Thus, the simplified expression is: \[ 27c + 27 \] For an even more factored form, we can factor out a 27: \[ 27(c + 1) \] So, the fully simplified expression is \( 27(c + 1) \).