2) \( -2+7-3+6-5+9-18 \)

Let's simplify the expression step by step: Start with \( -2 + 7 \) which equals \( 5 \). Then take \( 5 - 3 \) to get \( 2 \). Next, add \( 6 \) to get \( 8 \). From there, subtract \( 5 \) to reach \( 3 \). After that, add \( 9 \) to arrive at \( 12 \). Finally, subtract \( 18 \) to arrive at the final answer of \( -6 \). So, the whole expression simplifies to \( -6 \). Remember, when solving such math problems, it can help to group numbers strategically or keep a running total to avoid getting lost in the shuffle. Mistakes often happen when the signs are overlooked, so double-checking each step can save you from the dreaded faulty final answer.