Answer:

Step-by-step explanation:
So we start with:

To make this look more managable, lets seperate this into two binomials. Lets start with:

So how can we factor this? Lets look at what both the values have in common.
We immediatly see that they both have a coefficent of 2.
They also both have a h.
This means we can factor out a 2h from both and get:

Now lets move onto the other binomial we had:

Again, we can immediatly see that both values in this binomial have a 3.
Be careful however, make sure to factor out a -3, not a 3.
Another thing the two values have in common is a k.
This means we can factor out -3k to get:

Now lets reintroduce our first factored binomial back into this equation:

Notice that both factored binomials have (m-n)
Because of this we can neaten up our equation into:

How does this work?
Recall that the -3k will distrubute, or in otherwords multiply the (m-n) as
. It works the same way in this form as well, since when you use foil, you multiply 2h by both m and -n, and -3k by m and -n.
And we see, if we multiply the binomials out again, we get:

So our answer is:

Hope this helps! :3