Remember that a trinomial has three terms.
Like this guy:
Right now, we're really interested in a certain type of trinomial...
Remember FOIL?
We can multiply
 |
and get |  |
Hey -- that's our trinomial from above.
Basically, we'll be figuring out how to "undo" guys like
|
into their factors: |
|
You'll mostly be needing to know how to do this to solve equations like
(which we'll do later)