(a) \( 3 x+2 y+4+6 x+5 y+9 \) (b) \( 8 m+2 n+5-3 m-2 n+3 \) (c) \( 12 p+24 q-5-5 q-12 p-5 \)

Let's combine like terms in each of these expressions for clarity. For (a), adding \(3x\) and \(6x\) gives \(9x\), and combining \(2y\) and \(5y\) gives \(7y\). Finally, the constants \(4\), \(9\) combine to get \(13\), resulting in the expression: \(9x + 7y + 13\). For (b), we combine \(8m\) and \(-3m\) to get \(5m\), and for \(2n\) and \(-2n\), they cancel out to \(0\). Combining the constants \(5\) and \(3\) results in \(8\), leading to: \(5m + 8\). For (c), the \(12p\) terms cancel out, and combining \(24q\) with \(-5q\) results in \(19q\). The constants combine as follows: \(-5 - 5\) gives \(-10\), so we are left with: \(19q - 10\).