Distributive Property For Factoring (Let's Learn Factoring)

Brian McLogan
1.3K followers
400 Video Views·Jan 1, 2025
all right distributed property I know we
still have not got to factoring but I'm
telling you this is probably one of the
most important lessons for I want you to
be able to visualize what we're doing so
you can start to see why it is we're
trying to factor and what we are looking
for I kind of forgot some parentheses
here so what we need to do is remember
the kind of two rules for distributive
property if I have a * B plus C remember
this a needs to multiply by the B and
the C so this will be AB plus an AC and
then furthermore yeah we'll get to that
but what I want you to see here is
factoring is basically the process of
going from here to there right so we're
going to practice going from here to
here but what I want you to be able to
see is once each and every time that I
apply distributive property to each of
these problems what I want you to see is
look at the answer and kind of Look
Backwards kind of Follow That procord
backwards because that's where students
get hung up with factoring when we get
into the next lesson we're going to do
factoring we're going to get right into
it right and I have some lessons I have
tons of example problems but I want you
to be able to see where working forward
practice or factoring is going to be the
process of working backwards from the
distributive property so in this first
example I have 3 * x - 2 we're going to
multiply 3 * X and 3 - 2 so therefore I
have a 3X - a 6 and again remember what
I said if I wanted to factor 3x - 6 what
would that look like it would look like
this three times an x - 2 we'll talk
more about that later but I want you to
be able to see again I have a monomial
times a binomial need to multiply
everything times everything remember
numbers multiply by numbers variables
multiply by variables so therefore this
is going to be a 6 x^2 and a 2X * 5 I
can only multiply the 5 * the 2 so
that's going to be a positive 10x now we
get into a trinomial I don't have
anything for a trinomial here right but
the distributive property still works
ladies and gentlemen what we're simply
going to do is multiply the four times
everything and the x times everything
you could also use foil you can use a
foil phase there's a lot of techniques
that we use to help students remember
but this is about factoring so I'm
hoping assuming that probably already
know this I just want you to visualize
what happens when we multiply binomial
times a binomial that looks something
like this CU there is something
interesting about this it's the exact
same numbers except one's negative and
one is positive so4 * X is a -4x -4 * 4
is going to be a -16 x * X is going to
be a x^2 and x * 4 is going to be a
positive 4X so the one thing I want you
to recognize here is when I go ahead and
simplify this sorry that's a plus X squ
when I go ahead and simplify this I can
say well I have an x s right what about
my x's Well - 4x and posi 4X those are
going to add to zero so I don't have any
X terms and then I have
A6 that looks very similar to that
example I showed you with those little
boxes remember the x^2 minus one this is
going to be an x squ - 16 what about a
problem over here so again just follow
the same steps now typically I always
like to multiply the first two terms
first that's going to be our foil so we
do first so 2x * a 5x is going to be a
10 x^2 and then we do first outer so we
do 2x * negative 1 which would be your
outer terms 2x * 1 is going to be -2X
then we do our inner -1 * 5x is going to
be a 5x and then we do our last so we do
inner last 1 * 1 is going to be a
positive one now the big thing that
happens to students and the reason why I
had to spend some time doing this with
you guys is because when I teach
factoring or I make a video about how to
do factoring it is like without a doubt
students will always ask where' this
number go what happened to that number
like how' it just eliminate nothing is
being eliminated ladies and gentlemen
when I go and simplify this right the 4X
and the 4X those added to zero right I
didn't eliminate I just like poof and
it's gone but then when I combine them
when I simplifi them that is how I got
the ZX or no middle term over here when
I go to simplify this -2X minus a 5x is
a -7x right so when you go to simplify
there these are the only two terms that
I can go ahead and simplify I can't
combine everything with the 10x S I
can't combine anything with the one
these two terms though can simplify so
my final answer is a 10 x^2 minus a 7 x
+ 1 and guess what we're going to learn
how to factor from here to there
sometimes you could do it in your head
but this might be a little bit difficult
but I want you to be able to see this is
very very important because we're going
to get to this so if I don't study if I
don't teach it now then when I'm
teaching factoring I have to go back to
it and be like oh here's how this works
notice a 10 x^2 - 7 x + 1 if I was to
work my way backwards notice how 7x I
can break that up into a -2X and a 5x
then I can Factor things out it's just a
very important concept of this idea of
distributed property and factoring is
just going to be the reverse of that now
on the last one I threw in three terms
because it's important for you to
recognize when we need to disturb a
property we want to work one thing at a
time so I have a 2 * x -1 * x + 2 now
thankfully multiplication is cative so
it doesn't matter which one you do first
I would just maybe recommend doing your
two binomials first and then whatever
scaler you have then to go and do that
or whenever you have like three
binomials if you know you're moving on
something more advanced just pick two at
a time and then multiply everything by
the third one so I'm going to do two
times now let's multiply this out X now
I'm not going to show any lines here
we're going to kind of pick it up x * X
is an x^2 x * 2 is going to be a POS 2x-
1 * X is a x and - 1 * 2 is going to be
a -2 now if there wasn't a video that
was a little educational I would
probably simplify that in my head and
write it down but I don't know where
you're at so that's why I'm going to
work it in a little bit slower so x^2
let's see plus x - 2 now I can apply my
distributive property so we're doing a
lot of work here and that is going to
give us a 2 x^2 + a 2x - A4 and what's
reason what the reason why this is
important that I want you to be able to
see is when we're factoring one thing
we're always trying to do is trying to
say all right is there anything in
common that all of my terms have that I
can first factor that out and again when
I say the word Factor I'm saying rewrite
the expression as multiplication see
what happens here I multiply the two
times each and every one of these terms
when I'm given this problem and I want
to factor it what I'm basically doing is
dividing each of these these terms by
two because all of these terms share a
common factor right remember first video
they share a common factor of two
because two is divisible into each and
every one of these terms so if I divide
out of two and rewrite it as
multiplication I can rewrite it like
this then I would have to go into my
factoring techniques of trinomials
notice how I broke up the X into a 2X
and a Negative X and again how am I
going to do that well we're going to
learn that in the upcoming videos but I
just want you to see this process or I
want you to start visualizing the idea
of what we're trying to achieve with
factoring going from this term going in
the reverse of the distributed property
and guess what ladies and gentlemen it
is now time to get in factoring on the
next video
