The given expression is:

$4m + 9m + 6m - 2n$

First, combine the like terms involving $m$:

$(4m + 9m + 6m) = 19m$

Now the expression becomes:

$19m - 2n$

So, the simplified expression is:

$19m - 2n$

Would you like more details or have any questions?

Here are 5 related questions you could explore:

1. What if $m = 2$ and $n = 3$, how does the expression simplify numerically?
2. How would you factor out the common terms if there are any?
3. What happens if you introduce additional variables, say $p$ or $q$, into the equation?
4. Can you rewrite the expression using distribution?
5. How would the equation change if we had a square term like $m^2$ added?

Tip: Always combine like terms first when simplifying algebraic expressions!