3m-3n+am-an

The expression you provided is \(3m - 3n + am - an\).

You can factor this expression to simplify it. Notice that in the first two terms, \(3m\) and \(-3n\), you can factor out a 3, and in the last two terms, \(am\) and \(-an\), you can factor out \(a\).

Here’s how to factor the expression:

1. Factor out 3 from the first two terms: \[ 3(m - n) \]

2. Factor out \(a\) from the last two terms: \[ a(m - n) \]

So the entire expression becomes: \[ 3(m - n) + a(m - n) \]

Now you can combine the two factored terms since they share a common factor \((m - n)\): \[ (3 + a)(m - n) \]

Thus, the simplified form of the expression \(3m - 3n + am - an\) is: \[ (3 + a)(m - n) \]