What is \( -9 m-m \) simplified?

To simplify \( -9m - m \), you combine the like terms. You have \(-9m\) and \(-1m\) (since \(m\) is the same as \(1m\)). When you add these together, you get \((-9 - 1)m\), which simplifies to \(-10m\). So, the final simplified expression is \(-10m\). Now, if you were to visualize this, think of it as having 9 negative apples (that’s the \(-9m\)) and then taking away one more apple (the \(-m\)). So, you end up with 10 negative apples: \(-10m\)! This is a great way to practice combining like terms, which you'll encounter frequently in algebra. Just remember that keeping track of the signs is crucial.